Step-by-step explanation:
If 1 gallon = 3.785 litres
Then, 10 gallons = 37.85 litres
To solve you first need to pick out the most important information,
~Spent 20 minutes
~Each prob takes 2 minutes
Lets have y be the total time spent, and x the number of probs
(y/2) = x
Hope this helped!! ^-^
This does not look easy to factor, so I'd suggest using the quadratic formula:
-1 plus or minus sqrt( 1-4(3)(-5) )
x = -----------------------------------------------
2*3
-1 plus or minus sqrt(61)
= ------------------------------------
6
Thus, there are 2 real, unequal, irrational roots / solutions.
Since both equations are equal to y, we can just combine them like this:
1/3x-3=-x+5
1/3x=-x+8
4/3x=8 (since x is 1x which is 3/3x)
x=6
Plug x back in:
y=-6+5
y=-1
So x=6 and y=-1
Hope this helped!