Question

What is the value of ⁻2ₓ² + 8ₓ when x = ⁻6?

a- 24
b- ⁻24
c- ⁻72
d- ⁻120

Answer 1

Answer: D. -120

Explanation:

-2ₓ² + 8ₓ

-2(-6)^2 + 8(-6)

-2(36) + -48

-72 + -48

-120

Answer 2

-2 x^2 + 8x and x = -6 //Substitute x for -6.

-2(-6)^2 + 8(-6) //Solve.

NOTE: (-)^2 is +. Negative square is positive.

-2(36) - 48

-72 - 48 //Two negative numbers, add but has negative sign.

-120

Answer: D

//Hope this helps.