8 H + 4 J = 96
9 H + 5 J = 111
Fill in the blanks.
- 1 H = _____
- 1 J = _____
- 2 H + 4 J = _____
(a)
8 H + 4 J = 96 --- (1)
9 H + 5 J = 111 --- (2)
Make J the same.
LCM of 4 and 5 = 20
(1) x 5
40 H + 20 J = 480 --- (3)
(2) x 4
36 H + 20 J = 444 --- (4)
(a)
(3) - (4)
(40 H + 20 J) - (36 H + 20 J) = 480 - 444
40 H - 36 H + 20 J - 20 J = 36
4 H = 36
1 H = 36 ÷ 4 = 9
(b)
Substitute H = 9 into (1).
8 H + 4 J = 96
8 x 9 + 4 J = 96
72 + 4 J = 96
4 J = 96 - 72 = 24
1 J = 24 ÷ 4 = 6
(c)
2 H + 4 J
= 2 x 9 + 4 x 6
= 18 + 24
= 42
Answer(s): (a) 9; (b) 6; (c) 42