数学计算题,先化简,再代入,每道题都要具体的过程,最好写下来,有图,谢谢! !
3个回答
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(5)
原式=2t平方-2t-2-t平方+t+1+3t平方-3t-3
=(2t平方-t平方+3t平方)+(-2t+t-3t)+(-2+1-3)
=4t平方-2t-4
=2t(2t-1)-4
=2x(-1/2)[2x(-1/2)-1]-4
=-[-1-1]-4
=2-4
=-2
(6)
原式=(x-y)平方[2-9(x-y)-5-3+3(x-y)]-5
=(x-y)平方[-6-6(x-y)]
=-6(x-y)平方[1+x+y]
=-6*(-3+2)平方*[1-3-2]
=-6*1*(-4)
=24
原式=2t平方-2t-2-t平方+t+1+3t平方-3t-3
=(2t平方-t平方+3t平方)+(-2t+t-3t)+(-2+1-3)
=4t平方-2t-4
=2t(2t-1)-4
=2x(-1/2)[2x(-1/2)-1]-4
=-[-1-1]-4
=2-4
=-2
(6)
原式=(x-y)平方[2-9(x-y)-5-3+3(x-y)]-5
=(x-y)平方[-6-6(x-y)]
=-6(x-y)平方[1+x+y]
=-6*(-3+2)平方*[1-3-2]
=-6*1*(-4)
=24
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