How do you combine like terms in (5x^2+4)-(3x+7)+(2x^2-1)?

1 Answer
Mar 24, 2018

7x^2 - 3x - 4

Explanation:

Like terms are defined as terms with the same variables that are raised to the same power.

For example, the terms ax and bx^2 are NOT like terms because the coefficients a and b have variables (x and x^2, respectively) that are not raised to the same power.

In the expression (5x^2+4)-(3x+7)+(2x^2-1), the like terms are grouped as follows:
5x^2 and 2x^2

-3x (this is negative because the subtraction sign is "distributed" to the terms inside of the parentheses)

4, -7, -1 (the reason for why it's -7 is the same reason for why -3x is negative)

Add the terms in the groups up...
5x^2 + 2x^2 = 7x^2
-3x
4 - 7 - 1 = -4

Now you have the simplified expression: 7x^2 - 3x - 4