解方程组:(3x+2y)/3=(5x+3y)/4=-1

问题描述:

解方程组:(3x+2y)/3=(5x+3y)/4=-1

(3x+2y)/3=(5x+3y)/4=-1
(3x+2y)=-3 (1)
(5x+3y)=-4 (2)
(1)*3-(2)*2得
9x+6y-10x-6y=-9+8
-x=-1
x=1
y=-3


(3x+2y)/3=-1 =>3x+2y=-3 (1)
(5x+3y)/4=-1 =>5x+3y=-4 (2)
(1)*3 -(2)*2得:
9x-10x=-9+8
-x=-1
x=1,代入(1)解得y=-3