Answer:

Explanation:
We know we'll have to use the linear equation

Since
means gradient (or slope) we know that it's -3 since that's already indicated to us
All that we have to find now is b, and we can find this by plugging in the known values of x and y since we have the coordinate (2,-1)
We can plug these values in and solve for b

Therefore, in order to get the equation we just have to replace b with 5

Good luck!