algebra
posted by ???E .
in a week Mike ran 8km farther than Bill, while Pete ran 1 km less than 3 times as far as Bill.If pete ran 15 km farther than Mike, how many kilometers did Bill run?

M=B+8
P+1=3B
P15=M
put them in standard form..
MB=8
P3B=1
PM=15
Subtract the last from the middle..
3B+M=16
Now subtract the first equation.
2B=24
B=12
check me. If correct, then finish up the others. 
In a week Mike ran 8 km farther than Bill, while Pete ran 1 km less than 3 times as far as Bill.
If Pete ran 15 km farther than Mike, how many kilometers did Bill run?
Let m be how far Mike ran in km.
Let b be how far Bill ran in km.
Let p be how far Pete ran in km.
The given information is (1), (2), and (3).
(1) m = 8+b
(2) p = 3b – 1
(3) p = 15+m Use (1) to replace m in (3)
(4) p = 15+8+b Use (2) to replace p in (4)
(5) 3b – 1 = 15+8+b Subtract b from both sides. Add 1 to both sides.
(6) 2b = 24 Divide both sides by 2
(7) b = 12
Bill ran 12 km. 
thanks