# Ratio, Proportion and Percentages Puzzle -Critical Thinking 8

This kind of math puzzles is an educational activity for practicing children's math skills. It's also helpful for adults to have fun and challenge their brains!

## Challenge:

If $$5^x + 5^{x+1} + 5^{x+2}=\frac{31}{25}$$, what is the value of x?

$11.99 Satisfied 123 Students The correct answer is $$-2$$. Solve for x: $$5^x + 5^{x+1} + 5^{x+2}=\frac{31}{25}$$ The common factor is $$5^x$$. Then, $$5^x(1+5^1+5^2)=\frac{31}{25}⇒5^x(31)=\frac{31}{25}⇒5^x=\frac{\frac{31}{25}}{31}⇒$$ $$5^x=\frac{31}{25}÷\frac{31}{1}=\frac{31}{25}×\frac{1}{31}=\frac{1}{25}$$ $$\frac{1}{25}=5^{-2}$$ Then: $$5^x=5^{-2}⇒ x = -2$$ ### More math articles ### What people say about "Ratio, Proportion and Percentages Puzzle -Critical Thinking 8"? No one replied yet. X 30% OFF Limited time only! Save Over 30% SAVE$5

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