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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Friday April 03 2026
05:27:39 PM | Friday April 03 2026
05:27:39 PMFlip Answers |
| 1) | 105 * 95 = | | 1) 100 * 100 - 5 * 5 = 9975 |
| 2) | 407 * 393 = | | 2) 400 * 400 - 7 * 7 = 159951 |
| 3) | 409 * 391 = | | 3) 400 * 400 - 9 * 9 = 159919 |
| 4) | 198 * 202 = | | 4) 200 * 200 - 2 * 2 = 39996 |
| 5) | 93 * 107 = | | 5) 100 * 100 - 7 * 7 = 9951 |
| 6) | 106 * 94 = | | 6) 100 * 100 - 6 * 6 = 9964 |
| 7) | 97 * 103 = | | 7) 100 * 100 - 3 * 3 = 9991 |
| 8) | 396 * 404 = | | 8) 400 * 400 - 4 * 4 = 159984 |
| 9) | 410 * 390 = | | 9) 400 * 400 - 10 * 10 = 159900 |
| 10) | 405 * 395 = | | 10) 400 * 400 - 5 * 5 = 159975 |
| 11) | 51 * 62 + 49 * 62 = | | 11) ( 49 + 51) * 62 = 6200 |
| 12) | 31 * 83 + 69 * 83 = | | 12) ( 31 + 69) * 83 = 8300 |
| 13) | 34 * 38 + 34 * 62 = | | 13) ( 62 + 38) * 34 = 3400 |
| 14) | 72 * 164 + 72 * 36 = | | 14) ( 164 + 36) * 72 = 14400 |
| 15) | 242 * 55 - 55 * 42 = | | 15) ( 242 - 42) * 55 = 11000 |
| 16) | 161 * 81 + 81 * 39 = | | 16) ( 161 + 39) * 81 = 16200 |
| 17) | 151 * 49 - 51 * 49 = | | 17) ( 151 - 51) * 49 = 4900 |
| 18) | 56 * 50 + 50 * 44 = | | 18) ( 56 + 44) * 50 = 5000 |
| 19) | 236 * 62 - 62 * 36 = | | 19) ( 236 - 36) * 62 = 12400 |
| 20) | 54 * 76 + 146 * 76 = | | 20) ( 146 + 54) * 76 = 15200 |
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Score: ______________ | |
