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