Math Main Page => Exercises - Math III
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Goal: to practice how to make use of distributive property on special numbers, like (A + B) * (A - B) = A*A - B*B, A*C +B*C = (A + B ) *C, A*C - B*C = (A-B) * C
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Thursday February 19 2026
06:55:33 AM | Thursday February 19 2026
06:55:33 AMFlip Answers |
| 1) | 405 * 395 = | | 1) 400 * 400 - 5 * 5 = 159975 |
| 2) | 102 * 98 = | | 2) 100 * 100 - 2 * 2 = 9996 |
| 3) | 93 * 107 = | | 3) 100 * 100 - 7 * 7 = 9951 |
| 4) | 391 * 409 = | | 4) 400 * 400 - 9 * 9 = 159919 |
| 5) | 406 * 394 = | | 5) 400 * 400 - 6 * 6 = 159964 |
| 6) | 291 * 309 = | | 6) 300 * 300 - 9 * 9 = 89919 |
| 7) | 405 * 395 = | | 7) 400 * 400 - 5 * 5 = 159975 |
| 8) | 307 * 293 = | | 8) 300 * 300 - 7 * 7 = 89951 |
| 9) | 307 * 293 = | | 9) 300 * 300 - 7 * 7 = 89951 |
| 10) | 103 * 97 = | | 10) 100 * 100 - 3 * 3 = 9991 |
| 11) | 42 * 28 + 28 * 58 = | | 11) ( 58 + 42) * 28 = 2800 |
| 12) | 56 * 65 + 44 * 65 = | | 12) ( 44 + 56) * 65 = 6500 |
| 13) | 152 * 36 - 36 * 52 = | | 13) ( 152 - 52) * 36 = 3600 |
| 14) | 174 * 35 - 74 * 35 = | | 14) ( 174 - 74) * 35 = 3500 |
| 15) | 34 * 157 - 34 * 57 = | | 15) ( 157 - 57) * 34 = 3400 |
| 16) | 92 * 55 + 45 * 92 = | | 16) ( 55 + 45) * 92 = 9200 |
| 17) | 32 * 138 - 32 * 38 = | | 17) ( 138 - 38) * 32 = 3200 |
| 18) | 47 * 82 + 53 * 82 = | | 18) ( 53 + 47) * 82 = 8200 |
| 19) | 249 * 65 - 65 * 49 = | | 19) ( 249 - 49) * 65 = 13000 |
| 20) | 265 * 55 - 65 * 55 = | | 20) ( 265 - 65) * 55 = 11000 |
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Score: ______________ | |
