Question

Amir subtracted a quantity from the polynomial 3x² + 8x - 16 and produced the expression x^2- 4. What quantity did Amir subtract? Explain how

you got your answer.

Answer 1

`2x^2+ 8x -12`

Explanation:

Given

`P = 3x^2 + 8x - 16`

`Result = x^2 - 4`

Required

The quantity subtracted

Let the subtracted quantity be Q. So, we have:

`P - Q = Result`

`3x^2 + 8x - 16 - Q = x^2 - 4`

Collect like terms

`Q = 3x^2 - x^2+ 8x - 16 + 4`

`Q = 2x^2+ 8x -12`

The quantity subtracted is:
`2x^2+ 8x -12`