algebra 1
posted by julie .
a 100 foot cable is cut into two pieces.the first piece is 18 ft longer than the second. how long is each piece

Total length (given) ie. a+b = 100
a = b + 18
We can rewrite this b = a 18
Now solve it the normal way.
substitute for b in the first equation
a + b = 100
a + a  18 = 100
2a 18 = 100
2a = 100 + 18
2a = 118
a = 59
To get b:
go to equation and apply value of a in b = a 18
b = 59 18
ie. b = 41
to verify:
a + b should be = 100
a= 59 b = 41
59 + 41 = 100 !
Bingo!
Done! Hope this helps. 
The answer is 59 ft, 41 ft. X would equal 59 while y would equal 41