(a+7b)(7b-a)=49*b^2-a^2
(m+5)^2 - 3m(m-4)=-2*m^2+22*m+25
1) 1 - sin²α = cos²α
2) (1 + sinα)(1 - sinα) = 1 - sin²α = cos²α
11 - 2( 6 - 5z ) + 9z - 1 = 11 - 12 + 10z + 9z - 1 = 19z - 2
X(5+3x²-x-2+x-x²)-(3x-16+2x³)=x(3+2x²)-(3x-16+2x³)=3x+2x³-3x+16-2x³=16