## Selina Publishers Concise Mathematics Class 7 ICSE Solutions Chapter 5 Exponents (Including Laws of Exponents)

**Selina Publishers Concise Mathematics Class 7 ICSE Solutions Chapter 5 Exponents (Including Laws of Exponents)**

### Exponents Exercise 5A – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.

Find the value of:

(i) 6²

(ii) 7^{3}

(iii) 4^{4}

(iv) 5^{5}

(v) 8^{3}

(vi) 7^{5
}Solution:

Question 2.

Evaluate:

(i) 2^{3} x 4^{2}

(ii) 2^{3} x 5^{2}

(iii) 3^{3} x 5^{2}

(iv) 2^{2} x 3^{3}

(v) 3^{2} x 5^{2}

(vi) 5^{3} x 2^{4}

(vii) 3^{2 }x 4^{2}

(ix) (5 x 4)^{2
}Solution:

Question 3.

Evaluate:

Solution:

Question 4.

Evaluate :

Solution:

Question 5.

Which is greater :

(i) 2^{3} or 3^{2}

(ii) 2^{5} or 5^{2}

(iii) 4^{3} or 3^{4}

(iv) 5^{4} or 4^{5
}Solution:

Question 6.

Express each of the following in exponential form :

(i) 512

(ii) 1250

(iii) 1458

(iv) 3600

(v) 1350

(vi) 1176

Solution:

Question 7.

If a = 2 and b = 3, find the value of:

(i) (a + b)^{2}

(ii) (b – a)^{3}

(iii) (a x b)^{a}

(iv) (a x b)^{b}

Solution:

Question 8.

Express:

(i) 1024 as a power of 2.

(ii) 343 as a power of 7.

(iii) 729 as a power of 3.

Solution:

Question 9.

If 27 x 32 = 3^{x} x 2^{y}; find the values of x and y.

Solution:

Question 10.

If 64 x 625 = 2^{a} x 5^{b}; find :

(i) the values of a and b.

(ii) 2^{b} x 5^{a
}Solution:

### Exponents Exercise 5B – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.

Fill in the blanks:

In 5^{2} = 25, base = ……… and index = ……….

If index = 3x and base = 2y, the number = ………

Solution:

Question 2.

Evaluate:

(i) 2^{8} ÷ 2^{3}

(ii) 2^{3÷} 2^{8}

(iii) (2^{6})^{0}

(iv) (3^{o})^{6}

(v) 8^{3} x 8^{-5} x 8^{4}

(vi) 5^{4 } x 5^{3} + 5^{5}

(vii) 5^{4} ÷ 5^{3} x 5^{5}

(viii) 4^{4} ÷ 4^{3} x 4^{0}

(ix) (3^{5} x 4^{7} x 5^{8})^{0
}Solution:

Question 3.

Simplify, giving Solutions with positive index:

Solution:

Question 4.

Simplify and express the Solution in the positive exponent form :

Solution:

Question 5.

Evaluate

Solution:

Question 6.

If m^{2} = -2 and n = 2; find the values of:

(i) m + r^{2} – 2mn

(ii) m^{n} + n^{m}

(iii) 6m^{-3} + 4n^{2}

(iv) 2n^{3} – 3m

Solution: