y=(10+x)(50-5x)-8(50-5x)怎么解啊?像这一类的怎么解啊,有窍门.急,急,急,

求几个方程组的答案 ｛2x+y=2 {3x-y=7 x=?y=?{x+2y=50 {3x=2y+6 x=?y=?{x+y=40 {10x+8y=370 x、y=?{x+y=5.8 {y=3x+0.6 x=?y=? 解两道二元一次方程组.1.y=2x 10x+y=(10y+x)-362.x+y=5 50x*4=300y 解两道二元一次方程组..y=2x 10x+y=(10y+x)-362.x+y=5 50x*4=300y (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian (x-y)平方+5(x-y)-50 2X(x-150)=5X(3y+50) 10%x+6%y=8.5%X800怎样解? {2(x-y)=2y-x+1 ①50%x+10%y=8%*50 ② 3(2X+Y)+(2(2x-Y)=6 (8X+4y)-(10X-5Y)=2 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 解这些方程组 (1) 7x-2y=96 5x-3y=45 (2) 4x+2y=50 2x+3y=47 (3) 4x+2y=66 7x-3y=70(4) 11x+9y=49 13x-3y=17 (5) 2y-x=1 13x-8y=59 (6) 18x+29y=307 16x+28y=284 y+y+x=10,x+y+x=8,y=?,x=? (x+y)/6+(x-y)/10=1,(x+y)/6-(x-y)/10=5 X+Y-8X+10Y+41=O,求X/Y-Y/X的值 线性规划的图解法目标函数：π=4x+6y约束条件：{ 5x+10y≤50 8x+6y≤48 10y≤40 x;y≥0求作图表示! 2x-10=15x+30,6x－6=6x+2,9-3x=2x-8,5x=9x-50 ,5y-5=12-6y,15x-9=7x31最好的给补充财富和评满意答案.2题是9x-3（x-2）=6x+2 求X.Y 3(x+10)=8y-50 5x=10y+40步骤越详细越好, 急,求X.Y 3(x+10)=8y-50 5x=10y+40步骤越详细越好, X^2-Y^2+6X+10Y-30=0 X^2+Y^2-5X-8Y+21=0 X=?Y=?