Question

dados A=5x^2 + 7xy, B = 2x^2 -6y^2 e C = -9xy -3y^2 determine

a-) A+B-2C
b-) 2A-B-C

Answer 1

a)A+B-2.C
5x²+7xy+2x²-6y-2.(-9xy-3y²)
5x²+7xy+2x²-6y²+18xy+6y²
5x²+2x²-6y²+6y²+7xy+18xy
    7x² +25xy


b)2.A-B-C
2.(5x²+7xy)-(2x²-6y²)-(-9xy-3y)
10x²+14xy-2x²+12y²+9xy+3y²
10x²-2x²+12y²+3y²+14xy+9xy
     8x²+15y²+23xy


Espero ter colaborado.