What do you need to do before you can add the fraction

Make them have the same denominator.

1/2 + 1/3

=3/6 + 2/6

=5/6

Y=12.5x+225

Step-by-step explanation:

CHECK THE COMPLETE QUESTION BELOW;

A particular rocket taking off from the earth surface uses fuel at a constant rate of 12.5 gallons per minute the rocket initially contains 225 gallons of fuel determine a linear model and Y equals X plus B form for the amount of fuel Y as a function of the number of minutes x at the rocket has burned

We were told to determine a linear model, where Y equals X plus B form for the amount of fuel Y as a function of the number of minutes x at the rocket has burned.

If we interpret this we have, Y=X+B , this equation can be compared to the standard equation of slope intercept of

Y= mx+b

Where the m is the slope, and b is the initial value at "y" intercept.

From the question, we were told that Y denotes a function of the number of minutes x at the rocket has burned

The given slope from the question, which is the rate= 12.5 gallons per minute

The given initial value =225 gallons of fuel which the value of "b"

If we substitute into the equation of the slope, we have;Y=12.5x+225 which is the required linear model .