Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
4. Solving Exponential Equations
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Exercise 58 Page 304

Start by simplifying the exponential expression.

Solution:Yes, our friend is correct.
Explanation: See solution.

Practice makes perfect
We are given ( 1a)^x=b. We know that a>1 and b>1, but we need to determine the values of x that satisfy these conditions. Let's start by simplifying the equation.
(1/a)^x=b
1^x/a^x=b
1/a^x=b

To make this easier to comprehend, let's substitute a value for a. We will use 2. 1/2^x=b Notice that if we substitute any non-negative x-value into this equation, b will not be greater than one.

x b
0 1/2^0=1/1=1
1 1/2^1=1/2
2 1/2^2=1/4
3 1/2^3=1/8

This will continue as our x-values get larger and for any a-value greater than 1. Since no positive value of x will satisfy b>1, the value of x must be negative to satisfy the equation. Therefore, our friend is correct.