Question

If A = 2x - 722 + 3 and B = 4x2 - 12x, what is A + B?

A) -3x^2+10x+3

B) -3x^2-10x+3

C)3x^2-10x+3

D)6x^2-7x-9

Answer 1

B

Explanation:

Combine like terms. Like terms have same variable with same power.

2x & (-12x) are like terms and

-7x² & 4x² are like terms

A = 2x - 7x² + 3

B = 4x² - 12x

A + B = 2x - 7x² + 3 + 4x² - 12x

= 2x - 12x - 7x² + 4x² + 3

= (2-12)x + (-7 + 4)x² + 3

= -10x + (-3x²) + 3

= -3x² - 10x +3