Question

use the equation of the trend line to predict the cost of the electricity bill after 15 days. y = 3x + 5 (14,47) (5,20)

Explanation:

Step1: Identify the variable value

Let $x = 15$ (number of days).

Step2: Substitute into the equation

Substitute $x = 15$ into $y=3x + 5$. So $y=3\times15 + 5$.

Step3: Calculate the result

First, $3\times15=45$, then $45 + 5=50$.

Answer:

$50$