# Solve for X : 4x-1 × (0.5)3 - 2x = (1/8)^-x - Mathematics

Sum

Solve for x :  4x-1 × (0.5)3 - 2x = (1/8)^-x

#### Solution

4x-1 × (0.5)3 - 2x = (1/8)^-x

⇒ (2^2)^(x - 1) xx (1/2)^( 3 - 2x ) = ( 1/2^3 )^(-x)

⇒ 22x - 2 x 2-( 3 - 2x ) = (2 -3)- x

⇒ 22x - 2 - 3 + 2x = 23x

⇒ 24x - 5 = 23x
⇒ 4x - 5 = 3x
⇒ 4x - 3x = 5
⇒ x = 5

Concept: Solving Exponential Equations
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#### APPEARS IN

Selina Concise Mathematics Class 9 ICSE
Chapter 7 Indices (Exponents)
Exercise 7 (B) | Q 14.1 | Page 101