parentheses. For example,
3 ðxþ 2 Þ¼ 3 xþ 3 2 ¼ 3 xþ 6
5 ð 2 x 8 Þ¼ 5 2 x 5 8 ¼ 10 x 40
When you solve an equation, remove parentheses first, combine like terms
(i.e., 6xþ 8 x), and then solve as shown in the previous examples.
EXAMPLE:Solve forx: 2(3x12)¼ 36
SOLUTION:
2 ð 3 x 12 Þ¼ 36
2 3 x 2 12 ¼ 36 remove parentheses
6 x 24 ¼ 36
6 x 24 þ 24 ¼ 36 þ24 add 24
6 x¼ 60
61 x
61
¼
60
6
divide by 6
x¼ 10
EXAMPLE:Solve forx: 5(3xþ8) 10 x¼ 35
SOLUTION:
5 ð 3 xþ 8 Þ 10 x¼ 35
15 xþ 40 10 x¼ 35 remove parentheses
5 xþ 40 ¼ 35 combine 15x 10 x
5 xþ 40 40 ¼ 35 40 subtract 40
5 x¼ 5
51 x
51
¼
5
5
divide by 5
x¼ 1
REFRESHER IV Equations 75