the correct answer is C to this question
He didn’t multiply the equation by 1/2 in the second part so it threw his whole answer off. Hope this helps
Answer:
using the formula
we replace the coordinates
the we calculate
the answer will be square 100 which will give us 10
I'm guessing this is a slope problem, so the equation would be like this: y = mx + b where m is the slope and b is the y-intercept.

Using this,

Which is equal to,