Big Ideas Math Integrated I, 2016
BI
Big Ideas Math Integrated I, 2016 View details
4. Solving Exponential Equations
Continue to next subchapter

Exercise 10 Page 303

Rewrite the terms so that they have a common base.

x=5

Practice makes perfect

To solve the given exponential equation, we will start by rewriting the terms so that they have a common base.

216^x = 6^(x+10)
( 6^3 )^x = 6^(x+10)
6^(3x)= 6^(x+10)

Now we have two equivalent expressions with the same base. If both sides of the equation are equal, the exponents must also be equal. \

begin{gathered} 6^{3x}= 6^{x+10} \quad \Leftrightarrow \quad 3x = x+10 \end{gathered} Finally, we will solve the equation 3x = x+10.

3x = x+10
2x = 10
x=10/2
x = 5

To check our answer, we will substitute 5 for x in the given equation.

216^x = 6^(x+10)
216^5 ? = 6^(5+10)
â–¼
Simplify
216^5 ? = 6^(15)
( 6^3 )^5 ? = 6^(15)
6^(3*5) ? = 6^(15)
6^(15) = 6^(15) ✓

Since substituting 5 for x in the given equation produces a true statement, x=5 is the solution to our equation

.