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 January 22 2025
02:52:10 AM | Wednesday January 22 2025
02:52:10 AMFlip Answers |
| 1) | 410 * 390 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 91 * 109 = | | 2) 100 * 100 - 9 * 9 = 9919 |
| 3) | 391 * 409 = | | 3) 400 * 400 - 9 * 9 = 159919 |
| 4) | 208 * 192 = | | 4) 200 * 200 - 8 * 8 = 39936 |
| 5) | 101 * 99 = | | 5) 100 * 100 - 1 * 1 = 9999 |
| 6) | 94 * 106 = | | 6) 100 * 100 - 6 * 6 = 9964 |
| 7) | 105 * 95 = | | 7) 100 * 100 - 5 * 5 = 9975 |
| 8) | 203 * 197 = | | 8) 200 * 200 - 3 * 3 = 39991 |
| 9) | 290 * 310 = | | 9) 300 * 300 - 10 * 10 = 89900 |
| 10) | 204 * 196 = | | 10) 200 * 200 - 4 * 4 = 39984 |
| 11) | 140 * 27 - 27 * 40 = | | 11) ( 140 - 40) * 27 = 2700 |
| 12) | 141 * 71 + 71 * 59 = | | 12) ( 141 + 59) * 71 = 14200 |
| 13) | 247 * 81 - 81 * 47 = | | 13) ( 247 - 47) * 81 = 16200 |
| 14) | 52 * 48 + 52 * 152 = | | 14) ( 152 + 48) * 52 = 10400 |
| 15) | 152 * 50 - 52 * 50 = | | 15) ( 152 - 52) * 50 = 5000 |
| 16) | 51 * 54 + 149 * 54 = | | 16) ( 149 + 51) * 54 = 10800 |
| 17) | 74 * 238 - 74 * 38 = | | 17) ( 238 - 38) * 74 = 14800 |
| 18) | 79 * 268 - 79 * 68 = | | 18) ( 268 - 68) * 79 = 15800 |
| 19) | 164 * 47 - 64 * 47 = | | 19) ( 164 - 64) * 47 = 4700 |
| 20) | 70 * 161 - 70 * 61 = | | 20) ( 161 - 61) * 70 = 7000 |
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Score: ______________ | |
