Question: Solve $5^x + 5^{x+1} + 5^{x+2} = 155$


Solution:
Given,

$5^x + 5^{x+1} + 5^{x+2} = 155$

$or, 5^x + 5^x × 5^1 + 5^x × 5^2 = 155$

$or, 5^x ( 1 + 5 + 5^2) = 155$

$or, 5^x ( 31) = 155$

$or, 5^x × \dfrac{31}{31} = \dfrac{155}{31}$

$or, 5^x = 5$

$or, 5^x = 5^1$

$\therefore x = 1$
= Answer

Related Notes and Solutions:

Here is the website link to the notes of Indices.

#SciPiPupil