One person can do a certain job in ten minutes, and another person can do the same job in fifteen minutes. how many minutes will they take to do the job together?
if x represents how many minutes to do the job together, then how much of the job does the slowest person do?
1. x/15
2. x/10
3. 15/x

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.

b, i believe, but not sure.