6 p - 8 u = 24
7 u - 5 p = 27
Find the following values.
- 1 u
- 1 p
(a)
6 p - 8 u = 24 --- (1)
7 u - 5 p = 27 --- (2)
Make p the same.
(1) x 5
30 p - 40 u = 120 --- (3)
(2) x 6
42 u - 30 p = 162 --- (4)
(4) + (3)
42 u - 40 u = 120 + 162
2 u = 282
1 u = 282 ÷ 2 = 141
(b)
Substitute 1 u = 141 into (1).
6 p - 8 u = 24
6 p - 8 x 141 = 24
6 p - 1128 = 24
6 p = 24 + 1128
6 p = 1152
1 p = 1152 ÷ 6 = 192
Answer(s): (a) 141; (b) 192