Agardener can care for the green's property in 5 hours. if his assists him, they can complete the job in 4 hours. how long will it take the to do the job?

20 HOURS

Step-by-step explanation:

Both the gardener and the helper take 4 hours which means that working together they complete 1/4 of the job.

The gardener alone takes 5 hours meaning that he completes 1/5 of the job in 1 hour.

then,  to get the portion done by the helper in 1 hour we subtract fraction done by the gardener in 1hr from the fraction done by both in the same time.

1/4-1/5=1/20

to get the time the helper takes we find the reciprocal of 1/20 which is 20 HOURS

step-by-step explanation:

i dont get

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92