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 August 03 2026
09:13:08 AM | Monday August 03 2026
09:13:08 AMFlip Answers |
| 1) | 205 * 195 = | | 1) 200 * 200 - 5 * 5 = 39975 |
| 2) | 402 * 398 = | | 2) 400 * 400 - 2 * 2 = 159996 |
| 3) | 91 * 109 = | | 3) 100 * 100 - 9 * 9 = 9919 |
| 4) | 299 * 301 = | | 4) 300 * 300 - 1 * 1 = 89999 |
| 5) | 91 * 109 = | | 5) 100 * 100 - 9 * 9 = 9919 |
| 6) | 295 * 305 = | | 6) 300 * 300 - 5 * 5 = 89975 |
| 7) | 393 * 407 = | | 7) 400 * 400 - 7 * 7 = 159951 |
| 8) | 191 * 209 = | | 8) 200 * 200 - 9 * 9 = 39919 |
| 9) | 391 * 409 = | | 9) 400 * 400 - 9 * 9 = 159919 |
| 10) | 302 * 298 = | | 10) 300 * 300 - 2 * 2 = 89996 |
| 11) | 72 * 24 + 128 * 24 = | | 11) ( 128 + 72) * 24 = 4800 |
| 12) | 48 * 135 - 48 * 35 = | | 12) ( 135 - 35) * 48 = 4800 |
| 13) | 30 * 73 + 27 * 30 = | | 13) ( 27 + 73) * 30 = 3000 |
| 14) | 55 * 42 + 45 * 42 = | | 14) ( 45 + 55) * 42 = 4200 |
| 15) | 236 * 74 - 36 * 74 = | | 15) ( 236 - 36) * 74 = 14800 |
| 16) | 84 * 35 + 84 * 65 = | | 16) ( 65 + 35) * 84 = 8400 |
| 17) | 77 * 144 - 77 * 44 = | | 17) ( 144 - 44) * 77 = 7700 |
| 18) | 21 * 64 + 36 * 21 = | | 18) ( 36 + 64) * 21 = 2100 |
| 19) | 247 * 74 - 47 * 74 = | | 19) ( 247 - 47) * 74 = 14800 |
| 20) | 59 * 155 + 45 * 59 = | | 20) ( 155 + 45) * 59 = 11800 |
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Score: ______________ | |
