book Maths Puzzle Numerical Ability

I am having trouble getting problems into the quadratic form, for instance I don't undersatnd how to do put this problem into the right form.
(x+1)^2+2(x-2)=(x+1)(x-2)

Read Solution (Total 0)

book Other Question

use long division to divide the following polynomials:
1) divide 3x^4-7x^2+2x-10 by x-3
2) divide 6x^4+20x^3+13x^2-5x+2 by 2x^2-1
3) divide 4x+y by 3x-2
4) divide x^3-11 by x^2 explain what is wrong with the reasoning in the statement: since 20 is the opposite of -20, then 20 degrees ferhinent must be very hot, because -20 degrees celiuis is very cold.