已知Y=2X+3,求2(Y-2X)的3次方-4(2X-Y)2次方+6X-3Y
问题描述:
已知Y=2X+3,求2(Y-2X)的3次方-4(2X-Y)2次方+6X-3Y
答
Y=2X+3,
=>2X-Y=-3
2(Y-2X)的3次方-4(2X-Y)2次方+6X-3Y
=-2(2X-Y)^3-4(2X-Y)^2+3(2X-Y)
=-2*(-3)^3-4*(-3)^2+3*(-3)
=54-36-9
=9