using the two points we can find the slope of the line using (y2-y1)/(x2-x1):
(-5-1)/(5-(-10))=-6/15=-3/5. Then we can use the formula y-y1=m(x-x1). Out of the 5 variables, we have 4 of them: y=-3, y1=1, m=-3/5, and x1=-10. Now we just solve for x: -3-1=(-3/5)(x-(-10)).
-4=(-3/5)(x+10)
-4(-5/3)=x+10
20/3-10=x, so the x coordinate is -10/3.
