Respostas

2014-06-26T19:08:28-03:00
Basta substituir e voalá!

2x².y-xy = 2*(-2)²*4-(-2)*4 = 2*4*4+8 = 32+8 = 40

Keep Moving
2014-06-26T19:11:12-03:00
2x².y-xy      para x=-2 e y=4
2 . (-2)² . 4 - (-2).4
2 . 4 . 4 + 2 . 4
8 . 4 + 8
32 + 8
40