Learn Evaluate I 1 3 1 1 4 1 1 Ii 5 8 7x 8 5 4

from a handpicked tutor in LIVE 1-to-1 classes

from a handpicked tutor in LIVE 1-to-1 classes

# Evaluate

(i) {(1/3)^{−1 }− (1/4)^{−1}}^{−1 }(ii) (5/8)^{−7}× (8/5)^{−4}

**Solution:**

(i) {(1/3)^{−1 }− (1/4)^{−1}}^{−1}

According to the rules of exponents,

(a/b)^{−m} = (b/a)^{m}

{(1/3)^{−1 }− (1/4)^{−1}}^{−1}

= (3^{1 }− 4^{1})^{−1 }

= (3 − 4)^{−1}

= (−1)^{−1}

= (−1/1)^{1}= −1

(ii) (5/8)^{−7}× (8/5)^{−4}

According to the rules of exponents,

We know that, (a/b)^{−m} = (b/a)^{m}

(5/8)^{−7}× (8/5)^{−4}

= (8/5)^{7 }× (8/5)^{−4}

= (8/5)^{3 } [Since, a^{m}/a^{n} = a^{m - n}]

= 512/125

**☛ Check: **NCERT Solutions for Class 8 Maths Chapter 12

**Video Solution:**

## Evaluate (i) {(1/3)^{−1 }− (1/4)^{−1}}^{−1 }(ii) (5/8)^{−7}× (8/5)^{−4}

Class 8 Maths NCERT Solutions Chapter 12 Exercise 12.1 Question 6

**Summary:**

The value of the following expressions are (i) {(1/3)^{−1 }− (1/4)^{−1}}^{-1} = -1^{ }(ii) (5/8)^{−7}× (8/5)^{−4} = 512/125

**☛ Related Questions:**

- Evaluate (i) 3-2 (ii) (4)-2 (iii) (1/2)-5.
- Simplify and express the result in power notation with positive exponent. (i) (−4) 5 ÷ (−4) 8 (ii) (1 / 23) 2 (iii) (−3) 4 × (5/3) 4 (iv) (3 -7 ÷ 3 -10) × 3 -5 (v) 2 -3 × (−7) -3
- Find the value of (i) (30 × 4−1) × 22 (ii) (2−1 × 4−1) ÷ 2−2 (iii) (1/2)−2 + (1/3)−2 + (1/4)−2 (iv) (3−1 +4−1 + 5−1)0 (v) {(−2/3)−2}2
- Evaluate (i) (8−1× 53)/2−4 (ii) (5−1× 2−1)×6−1

Math worksheets and

visual curriculum

visual curriculum