5. Find each of the following products, using distributive laws:
a. 740 x 105
b. 245 x 1008
c. 996 x 367
d. 472 x1097
e. 439 x 997
f. 1553 x 198
Answers
Answer:
Distributive Property of multiplication over addition and subtraction is given as follows:
a × ( b + c ) = a × b + a × c
a × ( b - c ) = a × b - a × c
1).
740 × 105 = 740 × ( 100 + 5 )
= 740 × 100 + 740 × 5
= 74000 + 3700 = 77700
Thus, 740 × 105 = 77700
2).
245 × 1008 = 245 × ( 1000 + 8 )
= 245 × 1000 + 245 × 8
= 245000 + 1960 = 246960
Thus, 245 × 1008 = 246960
3).
947 × 96 = 245 × ( 100 - 4 )
= 947 × 100 - 947 × 4
= 94700 - 3788 = 90912
Thus, 947 × 96 = 90912
4).
996 × 367
= 367 × 996 = 367 × ( 1000 - 4 )
= 367 × 1000 - 367 × 4
= 367000 - 1468 = 365532
Thus, 996 × 367 = 365532
5).
472 × 1092 = 472 × ( 1100 - 8 )
= 472 × 1100 - 472 × 8
= 519200 - 3776 = 515424
Thus, 472 × 1092 = 515424
6).
580 × 64
= 64 × 580 = 64 × ( 500 + 80 )
= 64 × 500 + 64 × 80
= 32000 + 5120 = 37120
Thus, 580 × 64 = 37120
7).
439 × 997 = 439 × ( 1000 - 3 )
= 439 × 1000 - 439 × 3
= 439000 - 1317 = 437683
Thus, 439 × 997 = 437683
8).
1553 × 198 = 1553 × ( 200 - 2 )
= 1553 × 200 - 1553 × 2
= 310600 - 3106 = 307494
Thus, 1553 × 198 = 307494
Answer:
740× 105= 777,00
245× 1008= 246,960
996× 367= 365,532
472× 1097= 92,984