5y+6y-81=7y+102+65y~

Y. （2y-3)(-y+4)=(y-2)(y-5)-3y(y-7/3)解方程 1.5y+8y-6y=2y-3 先化简,在求值：6y-(y+2分之y + 2-y分之y)除以y³-4y-2y²+8分之y,其中y= x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9 (3y-1)/4-1=(5y-7)/6 9y-3-3=10y-14 9y-10y=-14+3+3 -y=-8 y=8 y-12/y=? 代数式y的平方+2y+7=6则5-4y的平方-8y= 解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6 (3x-4y)(5x-4y)-(7x-8y)(6y-5x) {2x+y/3-2y=0 2(2x+y)-5=7y 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7