A student showed the steps below while solving the equation [tex]$14=\log_5(2x-3)$[/tex] by graphing.

Step 1: Write a system of equations:
[tex]\[ y_1 = 14 \][/tex]
[tex]\[ y_2 = \log_5(2x-3) \][/tex]

Step 2: Use the change of base formula to rewrite the equations:
[tex]\[ y_1 = \log 14 \][/tex]
[tex]\[ y_2 = \frac{\log(2x-3)}{\log 5} \][/tex]

Step 3: Graph the two equations.



Answer :

Certainly! Let's solve the equation \(14 = \log_5(2x - 3)\) by graphing, guided by the student’s given steps.

### Step-by-Step Solution:

#### Step 1:
Identify the two equations to be graphed:
- The horizontal line representing the constant value: \(y_1 = 14\)
- The logarithmic function: \(y_2 = \log_5(2x - 3)\)

#### Step 2:
Use the change of base formula to rewrite the equations:
- For the horizontal line, it remains: \(y_1 = 14\)
- For the logarithmic function, we apply the change of base formula:
[tex]\[ \log_5(2x - 3) = \frac{\log(2x - 3)}{\log 5} \][/tex]
So, the equation transforms into: \(y_2 = \frac{\log(2x - 3)}{\log 5}\)

#### Step 3:
Graph the two equations on the same coordinate plane:
- The equation \(y_1 = 14\) is a horizontal line at \(y = 14\).
- The equation \(y_2 = \frac{\log(2x - 3)}{\log 5}\) is a transformed logarithmic function.

#### Step 4:
Find the intersection of the graphs:
- The solution to the equation \(14 = \log_5(2x - 3)\) is where the graphs of \(y_1\) and \(y_2\) intersect.
- This would be the \(x\)-coordinate of the point where the line \(y_1 = 14\) intersects the curve \(y_2 = \frac{\log(2x - 3)}{\log 5}\).

### Detailed clarification:
To find the point of intersection:

1. Set the equations equal to each other:
[tex]\[ 14 = \frac{\log(2x - 3)}{\log 5} \][/tex]

2. Solve for \(2x - 3\):
Multiply both sides by \(\log 5\):
[tex]\[ 14 \log 5 = \log(2x - 3) \][/tex]

3. Rewrite the equation in exponential form to solve for \(2x - 3\):
[tex]\[ 10^{14 \log 5} = 2x - 3 \][/tex]

4. Simplify the exponential term using properties of logarithms:
[tex]\[ 10^{14 \log 5} = (10^{\log 5})^{14} = 5^{14} \][/tex]
Thus, we have:
[tex]\[ 5^{14} = 2x - 3 \][/tex]

5. Solve for \(x\):
[tex]\[ 2x = 5^{14} + 3 \][/tex]
[tex]\[ x = \frac{5^{14} + 3}{2} \][/tex]

Therefore, the [tex]\(x\)[/tex] value where the two graphs intersect and which satisfies the original equation [tex]\(14 = \log_5(2x - 3)\)[/tex] is [tex]\(x = \frac{5^{14} + 3}{2}\)[/tex].

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