来自黄青松的问题
已知2x+3y=0,求下列代数式的值①5x+4y/3x-2y②x^2+xy-y^2/x^2-xy+y^2
已知2x+3y=0,求下列代数式的值
①5x+4y/3x-2y
②x^2+xy-y^2/x^2-xy+y^2
1回答
2020-12-09 21:39
已知2x+3y=0,求下列代数式的值①5x+4y/3x-2y②x^2+xy-y^2/x^2-xy+y^2
已知2x+3y=0,求下列代数式的值
①5x+4y/3x-2y
②x^2+xy-y^2/x^2-xy+y^2
2x+3y=02x=-3yx=-1.5y5x+4y/3x-2y=-1.5y*5+4y/-1.5y*3-2y=(-7.5y+4y)/(-4.5y-2y)=-3.5y/-6.5y=7/13x^2+xy-y^2/x^2-xy+y^2=(2.25y^2-1.5y^2-y^2)/(2.25y^2+1.5y^2+y^2)=-0.25y^2/3.75y^2=-1/15