Question

If 81^{2x – 3} = (243)⁴ find the value of x.
1. 4
2. 5
3. 3
4. 6
5. 7

Answer 1

Correct Answer - Option 1 : 4

Given:

81^{2x – 3} = (243)⁴

Concept used:

If x^a = x^b

Then a = b

Calculation:

81^{2x – 3} = (243)⁴

⇒ (3)^{4 × (2x – 3)} = (3)^{5 × 4}

⇒ 4 × (2x – 3) = 20

⇒ 2x – 3 = 5

⇒ 2x = 8

⇒ x = 4

∴ The value of x is 4.