6 V + 4 W = 24
7 V + 5 W = 29
Fill in the blanks.
- 1 V + 1 W = _____
- 1 V = _____
- 1 W = _____
(a)
6 V + 4 W = 24 --- (1)
7 V + 5 W = 29 --- (2)
(2) - (1)
(7 V + 5 W) - (6 V + 4 W) = 29 - 24
7 V - 6 V + 5 W - 4 W = 5
1 V + 1 W = 5 --- (3)
1 V + 1 W = 5
(b)
Make W the same.
LCM of 1 and 4 = 4
(3) x 4
4 V + 4 W = 20 --- (4)
(1) - (4)
(6 V + 4 W) - (4 V + 4 W) = 24 - 20
6 V - 4 V + 4 W - 4 W = 4
2 V = 4
1 V = 4 ÷ 2 = 2
(c)
Substitute 1 V = 2 into (3).
1 V + 1 W = 5
2 + 1 W = 5
1 W = 5 - 2 = 3
Answer(s): (a) 5; (b) 2; (c) 3