数学题=y(y+3)-4(y+3)2=(y+3)(y-4y-12)

数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y （2y-3)(-y+4)=(y-2)(y-5)-3y(y-7/3)解方程 1.5y+8y-6y=2y-3 解3y+5/3y-6=1/2+5y-4/2y-4 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 10y+2(7y-2)=5(4y+3)+3y怎么算 解方程：(y+4)/5+y+6=(y+8)/2-(y+4)/3 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 4x-2y-6y*-y-3x+5y* *=2 就是平方