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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Wednesday December 17 2025
01:03:45 AM | Wednesday December 17 2025
01:03:45 AMFlip Answers |
| 1) | 202 * 198 = | | 1) 200 * 200 - 2 * 2 = 39996 |
| 2) | 391 * 409 = | | 2) 400 * 400 - 9 * 9 = 159919 |
| 3) | 405 * 395 = | | 3) 400 * 400 - 5 * 5 = 159975 |
| 4) | 90 * 110 = | | 4) 100 * 100 - 10 * 10 = 9900 |
| 5) | 407 * 393 = | | 5) 400 * 400 - 7 * 7 = 159951 |
| 6) | 95 * 105 = | | 6) 100 * 100 - 5 * 5 = 9975 |
| 7) | 391 * 409 = | | 7) 400 * 400 - 9 * 9 = 159919 |
| 8) | 95 * 105 = | | 8) 100 * 100 - 5 * 5 = 9975 |
| 9) | 409 * 391 = | | 9) 400 * 400 - 9 * 9 = 159919 |
| 10) | 205 * 195 = | | 10) 200 * 200 - 5 * 5 = 39975 |
| 11) | 165 * 55 - 55 * 65 = | | 11) ( 165 - 65) * 55 = 5500 |
| 12) | 21 * 49 + 151 * 21 = | | 12) ( 151 + 49) * 21 = 4200 |
| 13) | 91 * 53 + 147 * 91 = | | 13) ( 147 + 53) * 91 = 18200 |
| 14) | 71 * 77 + 29 * 77 = | | 14) ( 29 + 71) * 77 = 7700 |
| 15) | 62 * 172 - 62 * 72 = | | 15) ( 172 - 72) * 62 = 6200 |
| 16) | 62 * 75 + 38 * 75 = | | 16) ( 38 + 62) * 75 = 7500 |
| 17) | 45 * 53 + 55 * 53 = | | 17) ( 55 + 45) * 53 = 5300 |
| 18) | 88 * 66 + 134 * 88 = | | 18) ( 134 + 66) * 88 = 17600 |
| 19) | 157 * 26 - 57 * 26 = | | 19) ( 157 - 57) * 26 = 2600 |
| 20) | 39 * 29 + 61 * 29 = | | 20) ( 61 + 39) * 29 = 2900 |
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Score: ______________ | |
