Bank Exam Algebra & Difference Tricks – Page 4 (Big Set)
Formulas • Fast Tricks • Step-by-Step Solutions
🔷 Core Formulas
a² − b² = (a − b)(a + b)
(a + b)² = a² + 2ab + b²
(a − b)² = a² − 2ab + b²
🔷 Difference of Squares (Fast Method)
Q1. 52² − 48²
= (52−48)(52+48)
= 4 × 100 = 400
Q2. 101² − 99²
= 2 × 200 = 400
Q3. 75² − 25²
= 50 × 100 = 5000
Q4. 64² − 36²
= 28 × 100 = 2800
Q5. 81² − 79²
= 2 × 160 = 320
Q6. 102² − 98²
= 4 × 200 = 800
Q7. 53² − 47²
= 6 × 100 = 600
Q8. 90² − 10²
= 80 × 100 = 8000
Q9. 120² − 80²
= 40 × 200 = 8000
Q10. 1001² − 999²
= 2 × 2000 = 4000
🔷 Expansion Tricks
Q11. (50 + 3)²
= 2500 + 300 + 9 = 2809
Q12. (60 − 4)²
= 3600 − 480 + 16 = 3136
Q13. (100 + 7)²
= 10000 + 1400 + 49 = 11449
Q14. (90 − 5)²
= 8100 − 900 + 25 = 7225
Q15. (200 + 4)²
= 40000 + 1600 + 16 = 41616
🔷 Mixed Algebra Tricks
Q16. 49 × 51
= (50−1)(50+1)
= 50² − 1² = 2500 − 1 = 2499
Q17. 98 × 102
= (100−2)(100+2)
= 10000 − 4 = 9996
Q18. 75 × 125
= (100−25)(100+25)
= 10000 − 625 = 9375
Q19. 48 × 52
= (50−2)(50+2)
= 2500 − 4 = 2496
Q20. 999 × 1001
= (1000−1)(1000+1)
= 1000000 − 1 = 999999
🔥 Topper Tricks
- Use (a+b)(a−b) whenever possible
- Convert numbers to base (50,100,1000)
- Use identity instead of multiplication
- Always look for pattern before solving
Final Tip
Identify Pattern → Apply Identity → Solve in Seconds
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