Given line l = ax + by + c = 0, b(its suppose to be the equal sign with the slash going thru it) 0

what is the slope of this function?

-a/b
a/b
b/a

The following division is being performed using multiplication by the reciprocal find the missing numbers is 5/12 divided by x/3 equals 5/12 times x/10 equals 1/x

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.