3x+4y=6 2x-3y=-13 用代入法解方程组

已知y=2x,z=3[y+x],试用含有x的代数值表示x+y+z 把方程3x+2y=3写成用含x的代式表示y的形式;________________. 解方程组：3x+2y=4 2x-3y=8求X和Y你们X=28/13 Y=-16/13 代进2式去算算，好像不对 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 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 化简求值：已知x、y满足：x^2+y^2-4x+6y+13=0 求代数式 的值.(3x+y)^2-3(3x-y)(x+y)-(x-3y)(x+3y)急用！ 把二元一次方程4x+2=3（2y+1）写成用含x的代 数式表示y的形式 初二上学期方程题 4x+y=5 5x+4y=63x-2y=1 2x+3y=13x-2y=7 7x+5y=32x+3y=17 2x-y=-4x+5y=6 2x+y=23x-6y=4 3x+2y=52x+y=73x-4y=53x+y=1x-2y=-1x+y=42x+3y=92x-3y=74x+5y=3x+y=20004x+6y=90003x+5y=113x-2y=42x+3y=215x-2y=5x+y=54x+3y=182x+3y=16x+4y=132x+3y=40x 4(x+y)-3(x-y)=14,x+y/2 + x-y/3=6 用简便方法能解吗? x+y/2+x-y/3=6,4(x+y)-5(x-y)=2用加减消元法解方程组 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40用加减法解 （2x-y+4）^2+|x+y|=o,则代数值4x+7y=—— 化简在求值 x²+x³-6y²+1-5x³-x+(y-x²)+6(x²+y²+y) x=3 y=2分之1化简在求值 x²+x³-6y²+1-5x³-x+(y-x²)+6(x²+y²+y) x=3 y=2分之1 先合并同类项在代值