Question

Exponents and radicals sample questions for 8th class

Answer 1

Answer:

Find the value of (40 + 4-1) × 22

Solution:

(40 + 4 -1) × 22 = (1 + ¼) × 4

= 5/4 x 4

= 5

2. Solve 3-4 and (½)-2

Solution:

We know, b-n = 1/bn

So, 3-4 = 1/34 = 1/81

And, (½)-2 = 1-2/2-2 = 22/12 = 4

3. Simplify the following expression and express the result in positive power notation:

(−4)5 ÷ (−4)8

Solution:

Using am ÷ an = am-n

(−4)5 ÷ (−4)8 = (-4)5/(-4)8

⇒ (-4)5-8 = 1/ (-4)3

4. Evaluate a2 × a3 × a-5

Solution:

a2 × a3 × a-5 = a2+3-5

= a5-5

= a0 = 1