31 + 3 u = 7 p
5 u - 22 = 6 p
Find the following values.
- 1 u
- 1 p
(a)
31 + 3 u = 7 p --- (1)
5 u - 22 = 6 p --- (2)
Make p the same.
(1) x 6
186 + 18 u = 42 p --- (3)
(2) x 7
35 u - 154 = 42 p --- (4)
(4) = (3)
35 u - 154 = 186 + 18 u
35 u - 18 u = 186 + 154
17 u = 340
1 u = 340 ÷ 17 = 20
(b)
Substitute 1 u = 20 into (2).
5 u - 22 = 6 p
5 x 20 - 22 = 6 p
100 - 22 = 6 p
78 = 6 p
1 p = 78 ÷ 6 = 13
Answer(s): (a) 20; (b) 13