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
(
x
2
−1)−3]−2x=3

(3)
3x+2y=5x+2
2(3x+2y)=11x+7

(4)
x+y
2
+
x−y
3
=6
4(x+y)−5(x−y)=2

(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...