8 A + 5 B = 82
9 A + 6 B = 93
Fill in the blanks.
- 1 A = _____
- 1 B = _____
- 4 A + 4 B = _____
(a)
8 A + 5 B = 82 --- (1)
9 A + 6 B = 93 --- (2)
Make B the same.
LCM of 5 and 6 = 30
(1) x 6
48 A + 30 B = 492 --- (3)
(2) x 5
45 A + 30 B = 465 --- (4)
(a)
(3) - (4)
(48 A + 30 B) - (45 A + 30 B) = 492 - 465
48 A - 45 A + 30 B - 30 B = 27
3 A = 27
1 A = 27 ÷ 3 = 9
(b)
Substitute A = 9 into (1).
8 A + 5 B = 82
8 x 9 + 5 B = 82
72 + 5 B = 82
5 B = 82 - 72 = 10
1 B = 10 ÷ 5 = 2
(c)
4 A + 4 B
= 4 x 9 + 4 x 2
= 36 + 8
= 44
Answer(s): (a) 9; (b) 2; (c) 44
