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(2xy-3)(2xy+3)+(xy+3)^2化简求值 x=1/5 y=-2
题目详情
(2xy-3)(2xy+3)+(xy+3)^2化简求值 x=1/5 y=-2
▼优质解答
答案和解析
x=1/5 , y=-2
xy=-2/5
(2xy-3)(2xy+3)+(xy+3)^2
=(2xy)²-9+(xy)²+6xy+9
=5(xy)²+6xy
=xy(5xy+6)
=(-2/5)[5(-2/5)+6]
=(-2/5)[-2+6]
=(-2/5)[4]
=-8/5
xy=-2/5
(2xy-3)(2xy+3)+(xy+3)^2
=(2xy)²-9+(xy)²+6xy+9
=5(xy)²+6xy
=xy(5xy+6)
=(-2/5)[5(-2/5)+6]
=(-2/5)[-2+6]
=(-2/5)[4]
=-8/5
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