Question

ME AJUDEM A RESOLVER PLEASE
$9a {}^{2} + 5b {}^{2} - (3b {}^{2} - 2a {}^{2} + ab)$
$3x {}^{2} + 5y - 7x {}^{2} + 4y$

Answer 1

Olá.

a) 9a^2+5b^2-(3b^2-2a^2+ab)=
9a^2+5b^2-3b^2+2a^2-ab=
9a^2+2b^2+2a^2-ab=
9a^2+2a^2+2b^2-ab=
11a^2+2b^2-ab.

b) 3x^2+5y-7x^2+4y=
3x^2-7x^2+5y+4y=
-4x^2+9y.