One month ruby worked 8 hours more than issac,and shetland worked 4 times as many hours as ruby. together they worked 136 hours. find the number of hours each person worked.

R=number of hours ruby worked
i=number of hours issac worked
s=number of hours shetland worked

ruby worked 8 more than issac
r=8+i

shetland worked 4 times as many as ruby
s=4r

total they worked 136
r+i+s=136

so

we gots
r=8+i
s=4r

for r=8+i
solve for i
minus 8 both sides
r-8=i

so

r+i+s=136
subsitute r-8 for i and 4r for s
r+r-8+4r=136
6r-8=136
add 8 to both sides
6r=144
divide both sides by 6
r=24

sub back

r-8=i
24-8=i
16=i

s=4r
s=4(24)
s=96

ruby worked 24 hours
issac worked 16 hours
shetland worked 96 hours

$15.06

Step-by-step explanation:

so u do 13.94 times 8% to get 1.12 cents

add it to the price to get 15.06