Question 607797
Alan's gas tank is 1/2 full. He fills it with 9 gallons and it is now 4/5 full.
 How many gallons can Alan's tank hold
:
Let f = no. of gallons in a full tank
:
{{{4/5}}}f = {{{1/2}}}f + 9
Multiply both sides by 10, results
2(4f) = 5f + 90
8f - 5f = 90
3f = 90
f = 90/3
f = 30 gallons