8 T + 6 U = 84
9 T + 7 U = 95
Fill in the blanks.
- 1 T = _____
- 1 U = _____
- 2 T + 2 U = _____
(a)
8 T + 6 U = 84 --- (1)
9 T + 7 U = 95 --- (2)
Make U the same.
LCM of 6 and 7 = 42
(1) x 7
56 T + 42 U = 588 --- (3)
(2) x 6
54 T + 42 U = 570 --- (4)
(a)
(3) - (4)
(56 T + 42 U) - (54 T + 42 U) = 588 - 570
56 T - 54 T + 42 U - 42 U = 18
2 T = 18
1 T = 18 ÷ 2 = 9
(b)
Substitute T = 9 into (1).
8 T + 6 U = 84
8 x 9 + 6 U = 84
72 + 6 U = 84
6 U = 84 - 72 = 12
1 U = 12 ÷ 6 = 2
(c)
2 T + 2 U
= 2 x 9 + 2 x 2
= 18 + 4
= 22
Answer(s): (a) 9; (b) 2; (c) 22
