I just need to ensure I have the equation correct.

A, B, and C build houses. Each house can be build in the following ways:

i) A and B work together for 6 hours, and C works for 4 hours

ii) A and B work together for 2 hours, and C works for 8 hours

iii) A works alone for 3 hours, B works alone for 1 hour, and Z works together for two hours

with A and B working together I'm confused on how to setup the equation

(x+y=6)+4z=1

(x+y=2)+8z=1

3x +1y + 2z =1

I don't understand how you have one equation inside another?? Try doing like they show

**here** (like they showed you back in regular algebra).

hours to complete job alone:

A: a hours

B: b hours

C: c hours

A&B: d hours

done per hour:

A: 1/a of the job

B: 1/b of the job

C: 1/c of the job

A & B: 1/d of the job

job done:

i) 6(1/d) + 4(1/c) = 1

ii) 2(1/d) + 8(1/c) = 1

iii) 3(1/a) + 1(1/b) +2(??) = 1

Note that:

d(1/a + 1/b) = 1

d((b+a)/ab = 1

d = ab/(b+a)

But I can't get any further because your statement of relationship (iii) doesn't make sense. Who is "Z", and who is he working with "together"? Also, "x" is standing for "A", "y" is standing for "B", and "z" is standing for "Z", but what letter are you using for "C"?

Please write back with clarification. Thanks.