Best Answer

The answer depends on the form of the equation and the domain.

For example,

  • there is no solution for x + 2 = 0 if the domain is positive integers, but there is if x can be a negative integer.
  • there is no solution for 2x = 1 for integer x but there is if x can be a rational number.
  • there is no solution for x^2 = 2 for rational x but there is if x can be an irrational number.
  • there is no real solution for x^2 = -2 for real x there is if x can be a complex number.

There are many other equations in one variable for which cannot be solved.

However, for simple equations, you may get a solution by making the same changes to both sides of the equation (with some exceptions, like division by zero, or taking square roots, etc) until you rename one side as the variable.

For example, to solve

(2x + 3)/5 = 9

Multiply both sides by 5: 2x + 3 = 45

Subtract 3 from both sides: 2x = 42

Divide both sides by 2: x = 21.

Solution of inequalities is the same except that if you multiply or divide by a negative number then the inequality changes direction.

User Avatar

Wiki User

โˆ™ 2014-09-10 19:43:08
This answer is:
User Avatar
Study guides


20 cards

A polynomial of degree zero is a constant term

The grouping method of factoring can still be used when only some of the terms share a common factor A True B False

The sum or difference of p and q is the of the x-term in the trinomial

A number a power of a variable or a product of the two is a monomial while a polynomial is the of monomials

See all cards
364 Reviews

Add your answer:

Earn +20 pts
Q: How can you solve an equation or inequality in one variable?
Write your answer...
Still have questions?
magnify glass
Related questions

What must be done get a variable alone on one side of an equation or inequality in order to solve the equation or inequality the answeranswer has eighteen letters with s being the second?

isolate the variable

What is it called when a when you get a variable alone on one side of an equation or inequality in order to solve the equation or inequality?

each of the four regions created on the coordinate plane by the x- and y-axes.

Can you solve for a variable in an expression or equation?

you can only solve for one in an equation so it can equal something

Can you solve a variable with an equation?

When an equation has a variable in it (only one), then there are only certainvalues the variable can have that will make the equation a true statement."Solving" the equation means finding those values for the variable.

What is 2x -2?


How does writing equivalent equations help you solve a system of equations?

You can write an equivalent equation from a selected equation in the system of equations to isolate a variable. You can then take that variable and substitute it into the other equations. Then you will have a system of equations with one less equation and one less variable and it will be simpler to solve.

Solve the inequality 9 h plus 2 minus 79?

This cannot be solved. Just like an equation, an inequality has to have at least one variable and at least one operator, such as less than, greater than, etc. Yours has no operator. Please restate your question.

When using the substitution to solve nonlinear system of equations you should first see if you can one variable if you can one variable in one of the equation in the system?

The general idea is to solve one of the equations for one variable - in terms of the other variable or variables. Then you can substitute the entire expression into another equation or other equations; as a result, if it works you should end up having one less equation, with one less variable.

How do you solve for the indicated variable?

Algebraically manipulate the equation until you have the indicated variable on one side of the equation and all of the other factors on the other side.

How doI solve system of equations by substitution?

Assuming the simplest case of two equations in two variable: solve one of the equations for one of the variables. Substitute the value found for the variable in all places in which the variable appears in the second equation. Solve the resulting equation. This will give you the value of one of the variables. Finally, replace this value in one of the original equations, and solve, to find the other variable.

What is an inequality that contains at least one variable?

Algebraic Inequality

What is an equation with one or two variables?

When you solve a one-variable equation, your goal is to isolate the variable.To isolate the variable means to make it be alone on one side of the equals sign.In the equation shown here, you can isolate the variable by subtracting 9 from both sides of the equation and simplifying

How would you prove that an inequality does have the same solution that an equation would have?

If you're given the inequality and the equation, then the way to prove that they have the same solution is to solve each one and show that the solutions are the same number. Don't strain yourself, though. An inequality and an equation never have the same solution.

What is the definition of algebraic inequality?

algebraic inequality, is an inequality that contains at least one variable.

How do use substitution when solving system of equations?

You use substitution when you can solve for one variable in terms of the others. By substituting, you remove one variable from the equation, which can then be solved. Once you solve for one variable, you can use substitution to find the other.

How do you solve log sub 9 parenthesis a over 27 closed parenthesis equals x minus 2?

Your equation has two variables in it ... 'a' and 'x'. So the solution is a four-step process: 1). Get another independent equation that relates the same two variables. 2). Solve one of the equations for one of the variables. 3). Substitute that into the other equation, yielding an equation in a single variable. Solve that one for the single variable. 4). Substitute that value back into the first equation, and solve it for the second variable.

How do you use different techniques to solve linear equations?

1. Elimination: Select two equations and a variable to eliminate. Multiply each equation by the coefficient if that variable in the other equation. If the signs of the coefficient for that variable in the resulting equations are the same then subtract one new equation from the other. If they have opposite signs then add them. You will now have an equation without that variable. Repeat will other pairs and you will end up with one fewer equation and one fewer variable. Repeat this process: after each round you will have one fewer equation and one fewer variable. Keep going until you are left with one equation in one variable. Solve that. Then work backwards solving for the other variables.2. Substitution: Select a equation and a variable. Make that variable the subject of the equation. The right hand side of this equation is an expression for that variable. Substitute this expression for the variable is each of the other equations. Again, one fewer equation in one fewer variable. Continue until you are left with one equation in one variable. Solve that. Then work backwards solving for the other variables.3. Matrix inversion: If A is the nxn matrix of coefficients, X is the nx1 [column] matrix of variables and B is the nx1 matrix of the equation constants, then X = A^-1*B where A^-1 is the inverse of matrix A.

When solving by the substitution method what happens when one variable cancels out?

That's exactly the purpose of the substitution method ... to get an equation with one less variable. When you have it, you solve it for the variable that's left.

a number when substituded in to an open sentence makes a true statement?

An equation or an inequality that contains at least one variable is called an open sentence. ... When you substitute a number for the variable in an open sentence, the resulting statement is either true or false. If the statement is true, the number is a solution to the equation or inequality.

How do you solve an inequality in one variable?

It depends on the specific inequality. In the simplest cases, it is solved just like an equation; except that you must be careful when multiplying and dividing - if you multiply or divide both sides by a negative number, you must switch the inequality sign. For instance, a "less-than" sign would be changed to a "greater-than" sign.

How solve this problem 32.5100?

32.5100 has excactly the same value as 32.51

Who do you solve -5 v-8 -9v plus 20?

I, for one, am certainly not going to solve that.It is an expression, not an equation nor inequality and expressions cannot be solved.

Four steps to the elimination method?

There are four steps in an algebraic elimination problem. These steps are: to find a variable with equal or opposite coefficients, if equal then subtract the equations but if opposite then add, solve one variable equation left, and then substitute known variable into other equation and solve. hi

What does it mean to solve a formula for a variable that appears on both sides?

It means that you manipulate the equation in such a way that the variable appears only on one side, by itself.

What is the easiest way you can solve inequalities?

Solve like any other math equation. One thing to remember; if you multiply or divide through by a negative number, reverse the inequality.