Question

Calculati : a) (3x+10y) - (5x+4y) - (7x-2y) b) (4a²-5ab) - (ab+3b²) -(a²-b²)

Answer 1

$a).(3x+10y)-(5x+4y)-(7x-2y)= \\ =3x+10y-5x-4y-7x+2y=-9x+8y \\ \\ b).(4a^2-5ab)-(ab+3b^2)-(a^2-b^2)= \\ =4a^2-5ab-ab-3b^2-a^2+b^2=3a^2-2b^2-6ab$