Question

$a = 3 { x}^{2} + 5xy + 10 {y}^{2}$
$b = 4 {x}^{2} - 3xy + 2 {y}^{2}$
$c = {x}^{2} + 8xy - {y}^{2}$
2c-(a+b) = ?
pls tell me the answer fast

Answer 1

a=3x²+5xy+10y²
b=4x²-3xy+2y²
c=x²+8xy-y²
2c-(a+b)
=2(x²+8xy-y²)-(3x²+5xy+10y²+4x²-3xy+2y²)
=2x²+16xy-2y²-7x²-2xy-12y²
=14xy-14y²-5x²