Question

FORMATIVE ASSESSMENT
Mental Maths
1. Write the value of (32).
2. In a', what is the base ?
3. What is the multiplicative inverse of 3-5 ?
4. The value of (1-100) is
(1/0).
a
4
5. The value of
X Х
is 1. Is it true ?
b
5
6. Simplifying and writing answer in the positive exponential form in (23-24) 5 x 216) gives
-3
3
7. Expressing
with a positive exponent gives
-5
8. By what number should
?
be divided so that the quotient is
2
4
?
9
9. For what value of a, a + =
16
10. The value of (4° -2°) x 52 is​

Answer 1

Answer:

Let the multiplicative inverse of 5−i be a+bi

Therefore we have (5−i)(a+bi)=1

⇒5a+b+i(5b−a)=1

⇒5a+b=1 and 5b−a=0

⇒a=5b

Substitute this in 5a+b=1, we get

b=

26

1

and a=

16

5

Therefore, multiplicative inverse is

26

(5+i)

.