Fractions 11
(iv) Hence,
3
4
−
7
16
=
12
16
−
7
16
=
5
16
− =
Problem 6. Simplify 4
2
3
− 1
1
6
4
2
3
− 1
1
6
is the same as
(
4
2
3
)
−
(
1
1
6
)
which is the
same as
(
4 +
2
3
)
−
(
1 +
1
6
)
which is the same as
4 +
2
3
− 1 −
1
6
which is the same as 3+
2
3
−
1
6
which
is the same as 3+
4
6
−
1
6
= 3 +
3
6
= 3 +
1
2
Thus, 4
2
3
− 1
1
6
= 3
1
2
Problem 7. Evaluate 7
1
8
− 5
3
7
7
1
8
− 5
3
7
=
(
7 +
1
8
)
−
(
5 +
3
7
)
= 7 +
1
8
− 5 −
3
7
= 2 +
1
8
−
3
7
= 2 +
7 × 1 − 8 × 3
56
= 2 +
7 − 24
56
= 2 +
− 17
56
= 2 −
17
56
=
112
56
−
17
56
=
112 − 17
56
=
95
56
= 1
39
56
Problem 8. Determine the value of
4
5
8
− 3
1
4
+ 1
2
5
4
5
8
− 3
1
4
+ 1
2
5
=( 4 − 3 + 1 )+
(
5
8
−
1
4
+
2
5
)
= 2 +
5 × 5 − 10 × 1 + 8 × 2
40
= 2 +
25 − 10 + 16
40
= 2 +
31
40
= 2
31
40
Now try the following Practice Exercise
PracticeExercise 5 Introduction to
fractions (answers on page 340)
- Change the improper fraction
15
7
into a
mixed number.
- Change the improper fraction
37
5
into a
mixed number.
- Change the mixed number 2
4
9
into an
improper fraction.
- Change the mixed number 8
7
8
into an
improper fraction.
- A box contains 165 paper clips. 60 clips
are removed from the box. Express this as
a fraction in its simplest form. - Order the followingfractions from the small-
est to the largest.
4
9
,
5
8
,
3
7
,
1
2
,
3
5
- A training college has 375 students of which
120 are girls. Express this as a fraction in its
simplest form.
Evaluate, in fraction form, the expressions given in
Problems 8 to 20.
8.
1
3
+
2
5
9.
5
6
−
4
15
10.
1
2
+
2
5
11.
7
16
−
1
4
12.
2
7
+
3
11
13.
2
9
−
1
7
+
2
3
- 3
2
5
− 2
1
3
15.
7
27
−
2
3
+
5
9
- 5
3
13
+ 3
3
4
- 4
5
8
− 3
2
5
- 10
3
7
− 8
2
3
- 3
1
4
− 4
4
5
+ 1
5
6
- 5
3
4
− 1
2
5
− 3
1
2