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(21x^4y^3-?+7x^2y^3)÷(-7x^2y)=+5xy-y是什么式子,

题目详情
(21x^4 y^3-?+7x^2 y^3)÷(-7x^2 y)= +5xy-y 是什么式子,
▼优质解答
答案和解析
(21x^4 y^3-?+7x^2 y^3)÷(-7x^2 y)
=(21x^4 y^3)/(-7x^2 y)-?/ (-7x^2 y)+(7x^2 y^3)/(-7x^2 y)
=-3x²y²-?/ (-7x^2 y)-y
/ (-7x^2 y)=5xy
=35x³y²
原式的等号左面的?是35x³y²;等号右面的?是-3x²y²-?;即:
(21x^4 y^3-35x³y² +7x^2 y^3)÷(-7x^2 y)=-3x²y²+5xy-y