8 p - 5 u = 22
4 u - 5 p = 23
Find the following values.
- 1 u
- 1 p
(a)
8 p - 5 u = 22 --- (1)
4 u - 5 p = 23 --- (2)
Make p the same.
(1) x 5
40 p - 25 u = 110 --- (3)
(2) x 8
32 u - 40 p = 184 --- (4)
(4) + (3)
32 u - 25 u = 110 + 184
7 u = 294
1 u = 294 ÷ 7 = 42
(b)
Substitute 1 u = 42 into (1).
8 p - 5 u = 22
8 p - 5 x 42 = 22
8 p - 210 = 22
8 p = 22 + 210
8 p = 232
1 p = 232 ÷ 8 = 29
Answer(s): (a) 42; (b) 29