Question

if A=x²+xy-6, B=2x²+1 and C=3x²+7-3xy find 2A+B-C
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Answer 1

solutions: given that

$a = {x }^{2} + xy - 6$

$b = 2 {x}^{2} + 1$

$c = 3 {x}^{2} + 7 - 3xy$

$2a + b - c$

$2( {x}^{2} + xy - 6) + 2{x}^{2} + 1 - (3 {x}^{2} + 7 - 3xy)$

$2 {x}^{2} + 2xy - 12 + 2 {x}^{2} + 1 - 3 {x}^{2} - 7 + 3xy$

${x}^{2} + 5xy - 18$

Answer 2

A=X^2+XY-6

B=2X^2+1

C=3X^2+7

2A+B-C=?

= 2(X^2+XY-6)+2X^2+1-3X^2+7

= 2X^2+2XY-12+2X^2+1-3X^2+7

= 4X^2-3X^2+2XY-12+8

= X^2+2XY-6  ans.