解下列方程或方程组. (1)x−74−5x+8/3=5/4 (2)4/3[3/2(x/2−1)−3]−2x=3 (3)3x+2y=5x+22(3x+2y)=11x+7 (4)x+y/2+x−y3=64(x+y)−5(x−y)=2
问题描述:
解下列方程或方程组.
(1)
−x−7 4
=5x+8 3
5 4
(2)
[4 3
(3 2
−1)−3]−2x=3x 2
(3)
3x+2y=5x+2 2(3x+2y)=11x+7
(4)
+x+y 2
=6x−y 3 4(x+y)−5(x−y)=2
答
(1)将方程去分母得:3(x-7)-4(5x+8)=15,整理得:x=-4;(2)将方程化简得:x-2-4-2x=3,整理得:x=-9;(3)两方程变形得:−2x+2y=2(1)−5x+4y=7(2),由(1)×2得:-4x+4y=4(3),由(3)-(2)得:x=-3...