remember distributive property
a(b+c)=ab+ac
a(b-c)=ab-ac
also
law of exponents

=

and
(a-b)(a+b)=a^2-b^2 (for question 14)
and (a+b)^2=a^2+2ab+b^2 (for question 15)
11.

=

=

12. 108+(28∛21)
13. (-2√6)+(4√10)
14.√(2x-3)-49
15. 2x+(20√x)+50
16. (3∛2)-(6∛4)-16
17. 42x-6