Page 28 - MarceAlgebra Demystified

CHAPTER 1 Fractions 15

6
84 12 ¼ 7: multiply 1 by 7 84 14 ¼ 6: multiply 9 by .
12 7 14 6
1 9 1 7 9 6 7 54 61
þ ¼ þ ¼ þ ¼
12 14 12 7 14 6 84 84 84

Examples

5 4
þ
6 15
6 ¼ 2 3 and 15 ¼ 3 5
The LCD is 2 3 5 ¼ 30; 30 6 ¼ 5 and 30 15 ¼ 2. Multiply 5 6 by 5 5
2
and 4 by .
15 2
5 4 5 5 4 2 25 8 33 11
þ ¼ þ ¼ þ ¼ ¼
6 15 6 5 15 2 30 30 30 10
17 5
þ
24 36

24 ¼ 2 2 2 3 and 36 ¼ 2 2 3 3
The LCD ¼ 2 2 2 3 3 ¼ 72; 72 24 ¼ 3 and 72 36 ¼ 2. Multiply
17 by 3 and 5 by .
2
24 3 36 2
17 5 17 3 5 2 51 10 61
þ ¼ þ ¼ þ ¼
24 36 24 3 36 2 72 72 72

Practice

11 5
1: ¼
12 18

7 9
2: þ ¼
15 20
23 7
3: þ ¼
24 16
3 7
4: þ ¼
8 20