解方程 (为了区分乘号和x,乘号用*表示) 7x-2.5x+3x-1.5x=15*4-6*3

2024-12-26 08:28:57
推荐回答(3个)
回答1:

解方程:
1)解:7x-2.5x+3x-1.5x=15×4-6×3
(7-2.5+3-1.5)x=60-18
6x=42
x=7
2)解:x/ 2+3/2x=7
(1/2+3/2)x=7
2x=7
x=3.5
3)解:6x-7=4x-5
6x-4x=7-5
2x=2
x=1
4)解:6(1/2-4)+2x=7-(1/3x-1)
6×1/2-6×4+2x=7-1/3x+1
3-24+2x=8-1/3x
2x-21=8-1/3x
5/3x=29
x=17.4
5)解:5x-1/4=(3x+1)/2-(2-x)/3
5x-1/4=3/2x+1/2-2/3+1/3x
5x-1/4=4/3x-1/6
5x-4/3x=1/4-1/6
11/3x=1/12
x=3/132
6)解:(3x+2)/2-1=(2x-1)/4-(2x+1)/5
3/2x+1-1=1/2x-1/4-2/5x-1/5
3/2x=1/10x-9/20
1/10x-3/2x=9/20
-7/5x=9/20
x=-9/28
(望采纳,谢谢)

回答2:

7x-2.5x+3x-1.5x=15*4-6*3
(7-2.5+3-1.5)x=60-18
6x=42
x=7
x/ 2+3/2x=7 3/2x应该是(3/2)x吧?如果不想用括号的话最好写成3x/2。下同
2x=7
x=7/2
6x-7=4x-5
6x-4x=7-5
2x=2
x=1
6(1/2-4)+2x=7-(3/2x-1)
3-24+2x=7-3x/2+1
2x-3x/2=7+1-3+24
x/2=29
x=58
5x-1/4=(3x+1)/2-(2-x)/3
60x-3=6(3x+1)-4(2-x)
60x-3=18x+6-8+4x
60x-18x-4x=6-8+3
38x=1
x=1/38
(3x+2)/2-1=(2x-1)/4-(2x+1)/5
10(3x+2)-20=5(2x-1)-4(2x+1)
30x+20-20=10x-5-8x-4
30x-10x+8x=-5-4-20+20
28x=-9
x=-9/28

回答3:

话说- - 这是一元一次方程吧。。。。
我6年级时就2元1次了= =、