Answer:
Step-by-step explanation:
Okay so we know that line on the triangle DEF that's parallel to the line BC is EF. This because they have the same slope and we can prove that while solving for slope-intercept form.
First we figure out our points for both the lines:
BC:
EF:
Now that we have our points we can use the slope formula to prove these two line have the same slope and are therefore parallel to eachother:
= Slope Formula
BC =
EF =
So now we proved that both of these lines have a slope of -1. Then we can use the slope intercept formula and one of the points from the line EF to find the y-intercept of the of line EF:
Let's use point =
We used the formula and found that the y-intercept was , so now we plug in all of our answers:
This is the complete answer but if you wanted to simplify it more you could write it as , cause as long as you make the x negative in the equation it will always be as if you multiplied it by -1.
