6 V + 2 W = 28
7 V + 3 W = 36
Fill in the blanks.
- 1 V + 1 W = _____
- 1 V = _____
- 1 W = _____
(a)
6 V + 2 W = 28 --- (1)
7 V + 3 W = 36 --- (2)
(2) - (1)
(7 V + 3 W) - (6 V + 2 W) = 36 - 28
7 V - 6 V + 3 W - 2 W = 8
1 V + 1 W = 8 --- (3)
1 V + 1 W = 8
(b)
Make W the same.
LCM of 1 and 2 = 2
(3) x 2
2 V + 2 W = 16 --- (4)
(1) - (4)
(6 V + 2 W) - (2 V + 2 W) = 28 - 16
6 V - 2 V + 2 W - 2 W = 12
4 V = 12
1 V = 12 ÷ 4 = 3
(c)
Substitute 1 V = 3 into (3).
1 V + 1 W = 8
3 + 1 W = 8
1 W = 8 - 3 = 5
Answer(s): (a) 8; (b) 3; (c) 5