Answer:
See picture attached
Step-by-step explanation:
A=1/10, b=1/12, c=1/15 (these are the rates for each worker...)
1.)
2(1/10)+4(1/12)+t/15=1
1/5+1/3+t/15=1
(3+5+t)/15=1
3+5+t=15
8+t=15
t=7
So it would take c 7 hours to finish the job.
2.)
1/40-1/60
(3-2)/120
1/120
The drain rate is 1/60. So you will need to find t when the tank is empty, while starting at 2/3 capacity...
2/3-t/60=0
(40-t)/60=0
40-t=0
t=40
It would take 40 minutes to empty the tank when it is 2/3 full.
W=2L-3
W*L=193
replace W with 2L-3: (2L-3)L=193
2L^2-3L-193=0
Cannot factor
are you sure the numbers are correct?
If it cannot be factored, use the quadratic formula to find out L, then you can find out W
use the Pythagorean theorem to find the diagonal. I don't see an easier way.
I'm not exactly sure of what you mean, but if the number (for example) were 2,3, and 6 you could say 2 and 6 multiply to get 6 and 6 divided by 2 would be 3 and so on. You could do this with any operation. Hope this helps, and sorry if this wasa little unclear.