To find the equation of a straight line, you first need to find the gradient;
Gradient=change in y/change in x
For our case we get,
(-4-1)/7-(-3)=-1/2
To find the equation, we choose one point i.e (7,-4)
So to find the equation, we use the same method that the used to calculate the gradient but the second point will be unknown i.e (x,y)
So: y-(-4)/(x-7)=-1/2
The equation is 2y+x=-1
+22 
