8/10 = 4/5 divide each by 2

Substitute the value of x = 2 to the equation:

Answer:
2x+5y=-15
ax+bx=c
slope=-a/b so -2/5 matches up with point slope form
then to get y intercept substitite x in point slope for 0 and solve for Y to get -3
then do c/b to get y intercept, so -15/5, which equals -3.
wind is predicted for 9 of the days.
rain is predicted for 18 of the days.
cloudiness if predicted for 27 of the days.
sunshine of predicted for 36 of the days.