Question

Calcule em seu caderno: a) (5x-1) x (5x+1) b) (a+b) x (a+b) c) (2x²-3x-6) x (5x-2) d) (2a+3/5b) x (a-1/2b)

Answer 1

$a) \ (5x-1) . (5x+1)=25x^2-1\\ \\ b) \ (a+b) . (a+b) = a^2+2ab+b^2\\ \\ c) \ (2x^2-3x-6) . (5x-2) = 5x^3-4x^2-15x^2+6x-30x+12=\\ \\ 5x^3-19x^2-24x+12\\ \\ d) \ (2a+\frac{3}{5}).(a-\frac{1}{2}b)=2a^2-ab+\frac{3}{5}a+\frac{3}{10}b$