F2 math

(3r + 4s)(4s - 3r)
= (4s + 3r)(4s - 3r)
= (4s)² - (3r)²
= 16s² - 9r²


Case I :
[(x/4) + 2y]²
= (x/4)² + 2*(x/4)*2y +(2y)²
= (x²/16) + xy + 4y²

Case II :
[(x + 2y)/4]²
= [x² + 2*x*2y + (2y)²]/4²
= (x²+ 4xy + 4y²)/16


A(x - 2) + 2B ≡ 6x - 14
Ax - 2A + 2B ≡ 6x - 14
Ax + (-2A + 2B) ≡ 6x - 14

Compare the x terms on the both sides :
A = 6

Compare the constant terms on the both sides :
-2A + 2B = -14
-2*6 + 2B = -14
-12 + 2B = -14
2B = -2
B = -1

In Q2,
is it factorize or expand?