What is the equation of the line passing through (1,8) and parallel to x+y=4 in slope intercept form

The system of equations graphed below has how many solutions?

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?