EduSahara™ Assignment
Name : Rationalising the Denominator
Chapter : Real Numbers
Grade : ICSE Grade VIII
License : Non Commercial Use
Question
1
1.
Rationalise the denominator of
1
(
−
7
√
3
)
(i)
(
−
1
21
)
(ii)
(
−
1
21
√
3
)
(iii)
(
−
1
7
)
(iv)
(
−
1
21
4
√
3
)
(v)
(
−
1
21
√
5
)
Question
2
2.
Rationalise the denominator of
1
(
√
4
+
√
7
)
(i)
(
−
4
3
+
1
3
√
7
)
(ii)
(
−
2
3
+
1
3
4
√
7
)
(iii)
(
−
2
3
+
1
3
√
7
)
(iv)
(
0
+
1
3
√
7
)
(v)
(
−
2
3
+
7
3
)
Question
3
3.
The rationalising factor of
(
−
4
√
80
)
=
(i)
√
5
(ii)
5
(iii)
√
7
(iv)
√
3
(v)
4
√
5
Question
4
4.
The rationalising factor of
(
8
√
3
+
8
√
4
)
=
(i)
(
8
−
16
)
(ii)
(
8
√
3
−
17
)
(iii)
(
8
√
6
−
16
)
(iv)
(
8
√
3
−
15
)
(v)
(
8
√
3
−
16
)
Question
5
5.
Rationalise the denominator of
1
(
−
5
√
4
+
9
√
8
)
(i)
(
5
274
+
9
274
√
2
)
(ii)
(
7
274
+
9
274
√
2
)
(iii)
(
5
274
+
9
274
4
√
2
)
(iv)
(
5
274
+
9
137
)
(v)
(
3
274
+
9
274
√
2
)
Question
6
6.
Rationalise the denominator of
(
√
5
−
√
3
)
(
−
√
6
+
√
2
)
=
(i)
(
−
1
4
√
27
+
1
4
√
18
−
1
4
√
10
+
1
4
√
6
)
(ii)
(
−
1
4
√
30
+
1
4
√
18
−
1
4
√
10
+
1
4
√
6
)
(iii)
(
−
1
4
√
30
+
1
4
√
18
−
1
4
√
10
+
1
4
√
8
)
(iv)
(
−
1
4
√
30
+
1
4
4
√
18
−
1
4
√
10
+
1
4
√
6
)
(v)
(
−
1
4
√
30
+
1
4
√
18
−
1
4
4
√
10
+
1
4
√
6
)
Question
7
7.
Rationalise the denominator of
(
2
√
2
−
√
6
)
(
5
√
9
+
5
√
6
)
=
(i)
(
2
5
√
2
−
1
5
√
6
−
2
15
4
√
12
+
2
5
)
(ii)
(
2
5
√
-1
−
1
5
√
6
−
2
15
√
12
+
2
5
)
(iii)
(
2
5
√
2
−
1
5
4
√
6
−
2
15
√
12
+
2
5
)
(iv)
(
2
5
√
2
−
1
5
√
6
−
2
15
√
12
+
2
5
)
(v)
(
2
5
√
2
−
1
5
√
6
−
2
15
√
12
+
4
5
)
Question
8
8.
Rationalise the denominator of
1
(
−
8
√
6
)
(i)
(
−
1
48
4
√
6
)
(ii)
(
−
1
48
√
9
)
(iii)
(
−
1
48
√
3
)
(iv)
(
−
1
8
)
(v)
(
−
1
48
√
6
)
Question
9
9.
Rationalise the denominator of
1
(
√
7
+
√
4
)
(i)
(
1
3
√
7
−
2
5
)
(ii)
(
1
3
√
4
−
2
3
)
(iii)
(
1
3
√
7
−
2
3
)
(iv)
(
1
3
√
7
−
2
)
(v)
(
1
3
√
9
−
2
3
)
Question
10
10.
The rationalising factor of
(
−
8
√
22
)
=
(i)
√
22
(ii)
4
√
22
(iii)
√
24
(iv)
22
(v)
√
20
Question
11
11.
The rationalising factor of
(
−
5
√
5
+
8
√
8
)
=
(i)
(
−
5
√
5
−
32
)
(ii)
(
−
5
√
2
−
16
√
2
)
(iii)
(
−
5
√
7
−
16
√
2
)
(iv)
(
−
5
√
5
−
16
4
√
2
)
(v)
(
−
5
√
5
−
16
√
2
)
Question
12
12.
Rationalise the denominator of
1
(
6
√
8
−
8
√
4
)
(i)
(
3
8
√
2
+
1
)
(ii)
(
3
8
√
1
2
+
1
2
)
(iii)
(
3
8
√
5
+
1
2
)
(iv)
(
3
8
√
2
+
1
4
)
(v)
(
3
8
√
2
+
1
2
)
Question
13
13.
Rationalise the denominator of
(
√
8
+
√
5
)
(
√
2
+
√
5
)
=
(i)
(
−
1
3
+
1
3
√
10
)
(ii)
(
1
3
+
1
3
√
10
)
(iii)
(
1
+
1
3
√
10
)
(iv)
(
1
3
+
1
3
4
√
10
)
(v)
(
1
3
+
10
3
)
Question
14
14.
Rationalise the denominator of
(
−
5
√
3
−
2
√
6
)
(
−
3
√
3
−
5
√
4
)
=
(i)
(
−
45
73
−
6
73
4
√
18
+
50
73
√
3
+
20
73
√
6
)
(ii)
(
−
45
73
−
6
73
√
18
+
50
73
4
√
3
+
20
73
√
6
)
(iii)
(
−
45
73
−
6
73
√
18
+
50
73
√
3
+
20
73
√
8
)
(iv)
(
−
47
73
−
6
73
√
18
+
50
73
√
3
+
20
73
√
6
)
(v)
(
−
45
73
−
6
73
√
18
+
50
73
√
3
+
20
73
√
6
)
Assignment Key
1) (ii)
2) (iii)
3) (i)
4) (v)
5) (i)
6) (ii)
7) (iv)
8) (v)
9) (iii)
10) (i)
11) (v)
12) (v)
13) (ii)
14) (v)
