Question

$a = 2y {}^{2} + 3x - x {}^{2} \: and \: b = 3x {}^{2} { - y {}^{} }^{2} \: and \: c = 5x {}^{2} { - 3xy}^{}$
then find A+B
A-B
B+C
B-C
A+B+C
A+B-C

Answer 1

$a \: + b \: =2 x {}^{2} + y {}^{2} + 3x \\ a - b = 3y {}^{2} - 4x {}^{2} + 3x \\ b - c = - 2x {}^{2} - y {}^{2} + 3xy \\ \: a + b + c = 7x {}^{2} + y {}^{2} - 3xy + 3x \\ a + b - c = - 3x {}^{2} + y {}^{2} + 3xy + 3x$