已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值
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![已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值](/uploads/image/z/7142026-58-6.jpg?t=%E5%B7%B2%E7%9F%A5x%E7%9A%84%E7%9B%B8%E5%8F%8D%E6%95%B0%E4%B8%BAy-6%2Cy%E7%9A%84%E5%80%92%E6%95%B0%E4%B8%BA2x%2C%E6%B1%82%E5%87%BA%E4%BB%A3%E6%95%B0%E5%BC%8F%285xy%2B4x%2B7y%29%2B3%282x-xy%29-%284xy-3y%29%E7%9A%84%E5%80%BC+%E5%B7%B2%E7%9F%A5x%E7%9A%84%E7%9B%B8%E5%8F%8D%E6%95%B0%E4%B8%BAy-6%2Cy%E7%9A%84%E5%80%92%E6%95%B0%E4%B8%BA2x%2C%E6%B1%82%E5%87%BA%E4%BB%A3%E6%95%B0%E5%BC%8F%285xy%2B4x%2B7y%29%2B3%282x-xy%29-%284xy-3y%29%E7%9A%84%E5%80%BC)
已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值
已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值
已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值
已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值
x的相反数为y-6,y的倒数为2x
x+y=6 2xy=1
(5xy+4x+7y)+3(2x-xy)-(4xy-3y)
=5xy+4x+7y+6x-3xy-4xy+3y
=-2xy+10x+10y
=10(x+y)-2xy
=60-1
=59
5、已知x的相反数为y-6,y的倒数为2x,求(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值。
∵-x=y-6,1/y=2x
∴x+y=6,2xy=1
∴ (5xy+4x+7y)+3(2x-xy)-(4xy-3y)
=5xy+4x+7y+6x-3xy-4xy+3y
=-2xy+10(x+y)
=-1+10*6
59
x的相反数为y-6则-x=y-6,x=6-y(x+y=6),y的倒数为2x则1/y=2x,2xy=1,
(5xy+4x+7y)+3(2x-xy)-(4xy-3y)化解=-2xy+10y+10y=-2xy+10(x+y)将x+y=6,和xy=1/2带如化解方程,得出原式=59