二元一次方程组7+x-3y/4=2x-y+5/3;10(x-y)-4(1-x)/3=y

显示全部楼层 · 2012-6-20 21:51:00

7+x-3y/4=2x-y+5/3;84+3(x-3y)=24x-4(y+5)84+3x-9y=24x-4y-2021x+5y=104 (1)10(x-y)-4(1-x)/3=y30(x-y)-4(1-x)=3y30x-30y-4+4x=3y34x-33y=4 (2)(1)*33+(2)*5得33*(21x+5y)+5*(34x-33y)=104*33+4*5693x+165y+170x-165y=3432+20863x=3452x=4y=4...

千问 · 2012-6-20 21:51:00

先化简，得12X-3Y-64=0......; 34X-33Y-4=0.........x11-,得，98X=700 解得，X=50/7代入,解得，Y=152/3...

千问 · 2012-6-20 21:51:00

先化简，得12X-3Y-64=0......; 34X-33Y-4=0.........x11-,得，98X=700 解得，X=50/7代入,解得，Y=152/3...