6 H + 4 J = 60
7 H + 5 J = 71
Fill in the blanks.
- 1 H = _____
- 1 J = _____
- 4 H + 4 J = _____
(a)
6 H + 4 J = 60 --- (1)
7 H + 5 J = 71 --- (2)
Make J the same.
LCM of 4 and 5 = 20
(1) x 5
30 H + 20 J = 300 --- (3)
(2) x 4
28 H + 20 J = 284 --- (4)
(a)
(3) - (4)
(30 H + 20 J) - (28 H + 20 J) = 300 - 284
30 H - 28 H + 20 J - 20 J = 16
2 H = 16
1 H = 16 ÷ 2 = 8
(b)
Substitute H = 8 into (1).
6 H + 4 J = 60
6 x 8 + 4 J = 60
48 + 4 J = 60
4 J = 60 - 48 = 12
1 J = 12 ÷ 4 = 3
(c)
4 H + 4 J
= 4 x 8 + 4 x 3
= 32 + 12
= 44
Answer(s): (a) 8; (b) 3; (c) 44
