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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Saturday December 21 2024
10:59:03 PM | Saturday December 21 2024
10:59:03 PMFlip Answers |
| 1) | 197 * 203 = | | 1) 200 * 200 - 3 * 3 = 39991 |
| 2) | 293 * 307 = | | 2) 300 * 300 - 7 * 7 = 89951 |
| 3) | 309 * 291 = | | 3) 300 * 300 - 9 * 9 = 89919 |
| 4) | 201 * 199 = | | 4) 200 * 200 - 1 * 1 = 39999 |
| 5) | 190 * 210 = | | 5) 200 * 200 - 10 * 10 = 39900 |
| 6) | 107 * 93 = | | 6) 100 * 100 - 7 * 7 = 9951 |
| 7) | 105 * 95 = | | 7) 100 * 100 - 5 * 5 = 9975 |
| 8) | 409 * 391 = | | 8) 400 * 400 - 9 * 9 = 159919 |
| 9) | 393 * 407 = | | 9) 400 * 400 - 7 * 7 = 159951 |
| 10) | 97 * 103 = | | 10) 100 * 100 - 3 * 3 = 9991 |
| 11) | 21 * 37 + 21 * 63 = | | 11) ( 37 + 63) * 21 = 2100 |
| 12) | 56 * 238 - 56 * 38 = | | 12) ( 238 - 38) * 56 = 11200 |
| 13) | 59 * 57 + 41 * 57 = | | 13) ( 59 + 41) * 57 = 5700 |
| 14) | 91 * 65 + 91 * 135 = | | 14) ( 135 + 65) * 91 = 18200 |
| 15) | 47 * 36 + 36 * 53 = | | 15) ( 53 + 47) * 36 = 3600 |
| 16) | 72 * 29 + 71 * 72 = | | 16) ( 29 + 71) * 72 = 7200 |
| 17) | 272 * 36 - 36 * 72 = | | 17) ( 272 - 72) * 36 = 7200 |
| 18) | 62 * 78 + 38 * 78 = | | 18) ( 38 + 62) * 78 = 7800 |
| 19) | 256 * 31 - 31 * 56 = | | 19) ( 256 - 56) * 31 = 6200 |
| 20) | 171 * 50 - 50 * 71 = | | 20) ( 171 - 71) * 50 = 5000 |
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Score: ______________ | |
