Question

5. Elena wanted to find the slope and y-intercept of the graph of 25x - 20y = 100.She decided to put the equation in slope-intercept form first. Here is her work-25x – 20y = 10020y = 100 – 25x5y = 5 --X-5. Describe Elena's mistake in her work above, and what the correct slopeand y-intercept of the line are.Your answer

Answer 1

Elena missed the minus sign.

Slope: 5/4

y-intercept: -5

Explanation:

We solve for and the equation of the statement to be able to express it in its slope-intercept form, like this:

`25x-20y=100`

we solve y:

`\begin{gathered} -20y=100-25x \\ y=(100)/(-20)+(25)/(-20)x \\ y=(5)/(4)x-5 \end{gathered}`

ELena's mistake was that she forgot the minus sign of the 20y, causing the result to completely change, therefore the correct slope and intercept would be 5/4 and -5 respectively.