-2-3=+7
21+1654+4
A variable is a letter that represents a number. An expression that contains at least one variable is called variable expression, also called algebraic expression. A variable expression has one or more terms. A term is a number, a variable, or a product of numbers and variables. For example,3(x^2)y + 2xy + x - 7 is a variable expression, where you have 4 terms.When working with variable expression, you often use the substitution principle:If a = b, then a may be replaced by b in any expression.The set of numbers that a variable may be represent is called replacement set, or domain, of the variable. To evaluate a variable expression, you replace each variable with one of its values and simplify the numerical expression that results.Example: Evaluate the expression 2x - 4y for x = 5 and y = -9.Solution:2x - 4y= 2(5) - 4(-9)= 10 + 36=46
4xy = 4(3)(-7) = - 84
(21-3)times(7+4)
5gz = 5 x 3 x 4 = 60
Unfortunately there is no expression to evaluate!
[10-(4*2)]*3
-2-3=+7
Okay, here is a postfix expression: 3 4 * 5 6 * + the evaluation: 3*4 + 5*6 12 + 30 42
2*3*4 = 24
2(1,0) - 3(2,-1) = (-4,3)
12 - 10 + 4 = 6
To evaluate the variable expression 3a + 2b, you need specific values for the variables a and b. Once you have those values, you substitute them into the expression and perform the arithmetic operations. For example, if a = 4 and b = 5, then 3(4) + 2(5) = 12 + 10 = 22. This gives you the final value of the expression.
Evaluate the following expression to 4*(12.25-4)/(9+2)
10
Evaluate the expression below when x = 2.3x2-2x+4