7x+1=3y4x+17=5y

7x+1=3y4x+17=5y 1.2(y-x）=3（x-y）3(x-4）=4（y+3)2.2x+1=3y4x-9y=8. 4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y求方程组的解 若4x^ay+x^2y^b=-3x^2y4x^ay+x^2y^b=-3x^2ya+b=? 【解方程组,一题】5x=10+5y,4x=6y【解方程组】5x=10+5y4x=6y min=7x+5x4x+3y-20≤0x-3y-2≤0x,y≥0min=7x+5y4x+3y-20≤0x-3y-2≤0y≥0 f(z)=ax+by,什么情况下f(z)取最大值?是不是ax=by时?原题是这样:f(z)=12x+7y4x+2y 4x - 3y = 8 -8x + 6y = 16 求x 和 y4x - 3y = 8-8x + 6y = 16求x 和 y 用公式法写二次函数的题目y=x^2-3x-4 y=2/1x^2-2x-1 y=x^2-3x y4x^2-4x+1y=-4x^2+3x 数学1元2次方程中的题目,谁会解3(X)的平方=4X-1Y(Y-2)=4-Y4X(1-X)=1T(T-2)-3(T)的平方=0(2X-3)的平方=X的平方1/2(X+3)的平方=2 几道初一合并同类项的题.各位高手,帮帮忙吧!-0.8a²b-6ab-1.2a²b+5ab+a²b2/3a²-1/2ab+3/4a²+ab-b²6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x²y4x²y-8xy²+7-4x²y+12xy²-43xm+3 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 5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3.5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3先化简,再求值； 帮忙解一些方程组(1)3x-2y=6 2x+3y=17 (2)5x+6y=15.2 3x-2y=-0.4(3)2(x+y)-3y=7 4(x-9)=3(y-2)(4)3(x+y)-4(x-y)=4 x+y/2+x-y/6=1 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4