Question

1. Choose the correct simplification of the expression −5x2(4x − 6x2 − 3).

30x4 − 20x3 + 15x2
−11x4 − x3 − 8x2
−30x4 + 20x3 − 15x2
30x4 + 20x3 + 15x2

2. Simplify (6x2 − 3 + 5x3) − (4x3 − 2x2 − 16).

2x3 − x2 + 21
−2x3 + x2 − 21
x3 + 8x2 + 13
−x3 − 8x2 + 13

Answer 1

1) 30x4 − 20x3 + 15x2

2) x3 + 8x2 + 13

Explanation:

Answer 2

1) 30x4 − 20x3 + 15x2

This is the answer to 1. Don't forget to rearrange the terms in ascending order. That can trip people up.

2) x3 + 8x2 + 13

Don't forget to check the terms sign. The subtraction symbol switches them all.