Answer:
The number of gallons of white paint mixed with 1 gallon of red paint is 5
Explanation:
Let
x ----> the number of gallons of red paint
y ----> the number of gallons of white paint
we have the ordered pairs
(5,25), (10,50) and (15,75)
Remember that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
In this problem we have a proportional relationship between the variables x and y
The ratio of the number of gallons of white paint mixed with 1 gallon of red paint is equal to the constant of proportionality k or slope of the linear equation

For (5,25) ----->

For (10,50) ----->

For (15,75) ----->

therefore
The number of gallons of white paint mixed with 1 gallon of red paint is
