Question

Its really hard for me to solve prob workin bakwards. i dnt get these math how to solve, pls teach me how these r can solve, if dnt i wont able to pass math exam, which i i hav to give within few days.

On Monday morning, Colin filled his car with gallons of gas, then used gallons driving. On Tuesday, he used up 2 gallons driving. On Tuesday night, his gas tank had gallons remaining. How much gas was in Colin's tank before he filled up on Monday morning?

Answer 1

another copy and paste fail

Answer 2

sorry ! i will do it now correctly

Answer 3

On Monday morning, Colin filled his car with 6 1/2 gallons of gas, then used 3 1/4 gallons driving. On Tuesday, he used up 2 gallons driving. On Tuesday night, his gas tank had 4 1/4 gallons remaining. How much gas was in Colin's tank before he filled up on Monday morning?

Answer 4

this is it

Answer 5

i am going to guess 3

Answer 6

lets say he started with "x" gallons of gas, then added 6 1/2 so now he has
\[x+6\tfrac{1}{2}\] gallons in the car
he then uses
\[5\tfrac{1}{4}\] so he has
\[x+6\tfrac{1}{2}-5\tfrac{1}{4}\] in the car

Answer 7

and you know that this is equal to
\[4\tfrac{1}{4}\] so put
\[x+6\tfrac{1}{2}-5\tfrac{1}{4}=4\tfrac{1}{4}\]and solve for x

Answer 8

\[x+6\tfrac{1}{2}=4\tfrac{1}{4}+5\tfrac{1}{4}=9\tfrac{1}{2}\]
\[x=9\tfrac{1}{2}-6\tfrac{1}{2}=3\]