更新时间:作者:小小条
1. 基本加法方程
题目:x + 7 = 15
解答:两边同时减去7:x + 7 - 7 = 15 - 7,x = 8

检验:8 + 7 = 15,正确
2. 基本减法方程
题目:x - 4 = 9
解答:两边同时加上4:x - 4 + 4 = 9 + 4,x = 13
检验:13 - 4 = 9,正确
3. 基本乘法方程
题目:5x = 30
解答:两边同时除以5:5x ÷ 5 = 30 ÷ 5,x = 6
检验:5 × 6 = 30,正确
4. 基本除法方程
题目:x ÷ 3 = 4
解答:两边同时乘以3:x ÷ 3 × 3 = 4 × 3,x = 12
检验:12 ÷ 3 = 4,正确
5. 两步方程(加法与乘法)
题目:2x + 5 = 17
解答:先减去5:2x + 5 - 5 = 17 - 5,2x = 12
再除以2:2x ÷ 2 = 12 ÷ 2,x = 6
检验:2 × 6 + 5 = 12 + 5 = 17,正确
6. 括号问题(分配律)
题目:3(x - 2) = 21
解答:分配3:3x - 6 = 21
加6:3x - 6 + 6 = 21 + 6,3x = 27
除以3:3x ÷ 3 = 27 ÷ 3,x = 9
检验:3(9 - 2) = 3 × 7 = 21,正确
7. 两边都有未知数
题目:4x - 7 = 3x + 5
解答:两边减3x:4x - 7 - 3x = 3x + 5 - 3x,x - 7 = 5
加7:x - 7 + 7 = 5 + 7,x = 12
检验:4 × 12 - 7 = 48 - 7 = 41,3 × 12 + 5 = 36 + 5 = 41,正确
8. 实际问题(减法)
题目:小明有一些糖果,他吃了5块后还剩10块。原来有多少块?
方程:x - 5 = 10
解答:x - 5 = 10,x = 10 + 5,x = 15
检验:15 - 5 = 10,正确
9. 倍数问题
题目:一个数的4倍是28,求这个数
方程:4x = 28
解答:4x = 28,x = 28 ÷ 4,x = 7
检验:4 × 7 = 28,正确
10. 括号问题(加法)
题目:2(x + 3) = 16
解答:分配2:2x + 6 = 16
减6:2x + 6 - 6 = 16 - 6,2x = 10
除以2:x = 5
检验:2(5 + 3) = 2 × 8 = 16,正确
11. 未知数在减数位置(易错)
题目:10 - x = 3
解答:两边加x:10 - x + x = 3 + x,10 = 3 + x
减3:10 - 3 = x,x = 7
检验:10 - 7 = 3,正确
12. 除法方程
题目:x ÷ 5 = 2
解答:两边乘以5:x = 2 × 5,x = 10
检验:10 ÷ 5 = 2,正确
13. 两边都有未知数(移动项)
题目:3x + 2 = 4x - 1
解答:两边减3x:3x + 2 - 3x = 4x - 1 - 3x,2 = x - 1
加1:2 + 1 = x,x = 3
检验:3 × 3 + 2 = 9 + 2 = 11,4 × 3 - 1 = 12 - 1 = 11,正确
14. 两步方程(减法与乘法)
题目:5x - 8 = 12
解答:加8:5x - 8 + 8 = 12 + 8,5x = 20
除以5:x = 4
检验:5 × 4 - 8 = 20 - 8 = 12,正确
15. 实际问题(和倍问题)
题目:一本书和一支钢笔共18元,书价是钢笔的2倍。求钢笔价格
方程:设钢笔x元,书2x元,x + 2x = 18
解答:3x = 18,x = 18 ÷ 3,x = 6
检验:钢笔6元,书12元,总18元,正确
16. 两步方程(加法与乘法)
题目:7x + 3 = 24
解答:减3:7x + 3 - 3 = 24 - 3,7x = 21
除以7:x = 3
检验:7 × 3 + 3 = 21 + 3 = 24,正确
17. 括号问题(减法)
题目:6(x - 1) = 30
解答:分配6:6x - 6 = 30
加6:6x - 6 + 6 = 30 + 6,6x = 36
除以6:x = 6
检验:6(6 - 1) = 6 × 5 = 30,正确
18. 未知数有负系数(易错)
题目:8 - 2x = 2
解答:加2x:8 - 2x + 2x = 2 + 2x,8 = 2 + 2x
减2:8 - 2 = 2x,6 = 2x
除以2:x = 3
检验:8 - 2 × 3 = 8 - 6 = 2,正确
希望这些题目和解答能帮助你掌握解方程的技巧!记得多练*,避免常见错误。关注我并转发分享收藏!
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