Question

6. If a + b + c = 15 and a2

+ b2

+ c2

= 83, find the value of a3

+ b3

+ c3 – 3abc.

7. Factorize:

(i) 6ab – b2

+ 12ac – 2bc

(ii) 9(2a – b)2 – 4(2a – b) – 13

8. If x3

+ ax2 – bx + 10 is divisible by x2 – 3x + 2, find the values of a and b.

Answer 1

7(1)

$6ab - {b }^{2} + 12ac - 2bc$
= b(6a-b) +2c(6a-b)
=(6a-b) (b+2c)