# Maths! Check Answers

posted by
**Jman** on
.

For questions 17–21, simplify the expression.

17. 7t4 • 7t4

49t8

14t4

49t16

14t8

18. –3(4x + 5)

7x + 15

7x – 15

–12x – 15

–12x + 15

19. 5k2(–6k2 – 2k + 6)

–30k3 + 3k2 + 30k

30k4 – 10k3 + 11k2

–k4 + 3k3 + 11k2

–30k4 – 10k3 + 30k2

20. (–8x) • 3x2

–5x3

–24x2

–24x3

–5x2

21. (7y2 – 3y) + (8y2 – 8y)

56y2 – 24y

15y2 – 11y

–y2 + 5y

y2 – 5y

MY ANSWERS

17. A

18. C

19. D

20. ?

21. B