Find the x and y intercepts or any other 2 points. (I advise you finding the y intercept though.)
then calculate for slope using:
y(2) - y(1)
________
x(2) - x(1)
The (2) and (1) are not exponents they are small numbers at the bottom of the numbers.
The slope is: 4
He used factoring to break it apart
This is your perfect answer
It is acute isosceles triangle