You can replace a variable with an equal value or expression. Just make sure the same variable always gets the same value or expression.
No, expressions do not have equal signs. Equations do, though. You can think of it like this: Equtions have EQUAl signs, while expressions do not.No, an expression cannot have an equal sign. If it were to have an equal sign, it would then be an equation.
Expressions cannot be solved. Only equations or inequalities may be solved. Also, there is no symbol between 3i and 5.
If an expression does not have a common factor, then it is called a "prime" expression.
Yes. Any number, or expression, is equal to itself. An equation such as:x + 5 = x + 5 is true for ANY value of "x".
The question is about an oxymoronic expression. A constant cannot be a variable and a variable cannot be a constant!
No, you can only simplify an expression. To solve for a variable, it must be in an equation.
It is a linear expression in two variables. As an expression it cannot be solved. Furthermore, to solve equations in two variables you need at least two linear equations.
neither, an independent variable is a variable not being changed in the process of a science experiment. A variable in math cannot be described, only purpose of a variable is to take place of a number that you are trying to figure out in some equations. Others are equations with no solution.
An expression cannot be solved; an equation or an inequality may be.
There is, unfortunately, n equation in the question: only an expression. An expression cannot be solved for a variable.
You cannot work a simultaneous equation. You require a system of equations. How you solve them depends on their nature: two or more linear equations are relatively easy to solve by eliminating variables - one at a time and then substituting these values in the earlier equations. For systems of equations containing non-linear equations it is simpler to substitute for variable expression for one of the variables at the start and working towards the other variable(s).
You cannot because the expression still contains the unknown variable y.
You will apply them when solving quadratic equations in which the quadratic expression cannot be factorised.
It is an expression in the variable y. Since it is not an equation it cannot be solved.