题目内容
计算:
(1)[x(x2y2-xy)-y(x2-x3y)]÷3x2y;
(2)已知:xm=3,xn=2,求x3m+2n.
(1)[x(x2y2-xy)-y(x2-x3y)]÷3x2y;
(2)已知:xm=3,xn=2,求x3m+2n.
(1)原式=(x3y2-x2y-x2y+x3y2)÷3x2y
=(2x3y2-2x2y)÷3x2y
=
xy-
;
(2)∵xm=3,xn=2,
∴x3m+2n=(xm)3•(xn)2=27×4=108.
=(2x3y2-2x2y)÷3x2y
=
2 |
3 |
2 |
3 |
(2)∵xm=3,xn=2,
∴x3m+2n=(xm)3•(xn)2=27×4=108.
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