化简求值:[(1/2a-b)^2+(1/2a+b)^2]`(2a^2-1/2b^2),其中a=-3,b=4

问题描述:

化简求值:[(1/2a-b)^2+(1/2a+b)^2]`(2a^2-1/2b^2),其中a=-3,b=4

=(a^2/2+2b^2)(2a^2-b^2/2)
=(9/2+2*4^2)(2*9-8)
=365

:[(1/2a-b)^2+(1/2a+b)^2]`(2a^2-1/2b^2),
=(a²/4-ab+b²+a²+ab+b²)(2a²-b²/2)
=(a²/2+2b²)(2a²-b²/2)
当a=-3,b=4时
原式=(9/2+32)(18-8)
=36.5×10
=365