20 and 7 Because 4x5 = 20
The answer is
X =3
because they both equal the amounts given
We have the function
and we want to find a function that has the same y-intercept than the previous function.
First, let's find the y-intercept by subtituting 0 for 'x'.

Now that we found that y-intercept =-3, any lineal function of the type:
will have the same y-intercept. Where 'a' can take all the real values.
Also, any quadratic function of the type:
will have the same y-intercept. Where 'a' and 'b' can take all the real values.
Given, Shelby made 5 quarts of juice for a picnic.
We know that 1 quart of juice = 4 cups of juice.
Here we will have to convert 5 quarts to cups.
As for 1 quart there are 4 cups, to find 5 quarts we have to multiply 4 times 5.
So 5 quarts of juice =
cups of juice.
We know that, 
5 quarts of juice = 20 cups of juice.
We have got the required answer here.
Shelby made 20 cups of juice there in the picnic.