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| source: ncert |
| topic: algebra |
| class_level: class_7 |
| chapter: ch4 |
| difficulty: beginner |
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| |
| Class 7 | Ch4: Simple Equations |
| Equation: LHS=RHS. Solution: value making equation true. |
| Transposition: move term to other side changing sign. +a becomes -a, ×a becomes ÷a. |
| Golden rule: same operation on BOTH sides. |
| Steps: collect variables one side, constants other side, divide by coefficient. |
| Solve 2x+7=19: 2x=12, x=6. Verify: 2(6)+7=19 correct. |
| Solve 3(y-4)=2y+1: 3y-12=2y+1, y=13. Verify: 3(9)=27=2(13)+1 correct. |
| Cross multiply: (x+2)/3=(x-1)/4 → 4(x+2)=3(x-1) → x=-11. |
| Word problem: consecutive integers sum=53. n+(n+1)=53 → n=26. Integers: 26,27. |
| Always verify by substituting back. Expand brackets BEFORE transposing. |
