Let’s solve each equation one by one. We’re looking for the value of
x that makes each equation true.
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1. 2x + 3 = 21
Subtract 3 from both sides:
→ 2x = 18
Divide by 2:
→ x = 9
✔
---
2. 3 + 2x = 21
Same as above — just reordered.
Subtract 3:
→ 2x = 18
Divide by 2:
→ x = 9
✔
---
3. 2x – 3 = 21
Add 3 to both sides:
→ 2x = 24
Divide by 2:
→ x = 12
✔
---
4. 3 – 2x = 21
Subtract 3 from both sides:
→ –2x = 18
Divide by –2:
→ x = –9
✔
---
5. 2x + 4 = 21
Subtract 4:
→ 2x = 17
Divide by 2:
→ x = 8.5 or 17/2
✔
---
6. 2x + 23 = 21
Subtract 23:
→ 2x = –2
Divide by 2:
→ x = –1
✔
---
7. x/2 + 3 = 21
Subtract 3:
→ x/2 = 18
Multiply by 2:
→ x = 36
✔
---
8. 3x + 3 = 21
Subtract 3:
→ 3x = 18
Divide by 3:
→ x = 6
✔
---
9. 6x + 3 = 21
Subtract 3:
→ 6x = 18
Divide by 6:
→ x = 3
✔
---
10. x/4 + 3 = 21
Subtract 3:
→ x/4 = 18
Multiply by 4:
→ x = 72
✔
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All equations solved correctly. Each has a unique solution for x.
Final Answer:
x = 9, 9, 12, –9, 8.5, –1, 36, 6, 3, 72
Parent Tip: Review the logic above to help your child master the concept of two step equation worksheet.
