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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Monday June 16 2025
02:58:50 AM | Monday June 16 2025
02:58:50 AMFlip Answers |
| 1) | 91 * 109 = | | 1) 100 * 100 - 9 * 9 = 9919 |
| 2) | 397 * 403 = | | 2) 400 * 400 - 3 * 3 = 159991 |
| 3) | 209 * 191 = | | 3) 200 * 200 - 9 * 9 = 39919 |
| 4) | 295 * 305 = | | 4) 300 * 300 - 5 * 5 = 89975 |
| 5) | 93 * 107 = | | 5) 100 * 100 - 7 * 7 = 9951 |
| 6) | 306 * 294 = | | 6) 300 * 300 - 6 * 6 = 89964 |
| 7) | 307 * 293 = | | 7) 300 * 300 - 7 * 7 = 89951 |
| 8) | 91 * 109 = | | 8) 100 * 100 - 9 * 9 = 9919 |
| 9) | 302 * 298 = | | 9) 300 * 300 - 2 * 2 = 89996 |
| 10) | 293 * 307 = | | 10) 300 * 300 - 7 * 7 = 89951 |
| 11) | 242 * 72 - 72 * 42 = | | 11) ( 242 - 42) * 72 = 14400 |
| 12) | 158 * 78 + 78 * 42 = | | 12) ( 158 + 42) * 78 = 15600 |
| 13) | 261 * 40 - 40 * 61 = | | 13) ( 261 - 61) * 40 = 8000 |
| 14) | 149 * 28 - 49 * 28 = | | 14) ( 149 - 49) * 28 = 2800 |
| 15) | 62 * 29 + 62 * 71 = | | 15) ( 29 + 71) * 62 = 6200 |
| 16) | 91 * 140 + 60 * 91 = | | 16) ( 140 + 60) * 91 = 18200 |
| 17) | 80 * 264 - 64 * 80 = | | 17) ( 264 - 64) * 80 = 16000 |
| 18) | 253 * 22 - 22 * 53 = | | 18) ( 253 - 53) * 22 = 4400 |
| 19) | 74 * 243 - 43 * 74 = | | 19) ( 243 - 43) * 74 = 14800 |
| 20) | 54 * 21 + 21 * 46 = | | 20) ( 46 + 54) * 21 = 2100 |
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Score: ______________ | |
