White paint

A painter needs 4 1/2 gallons of white paint. He has 1 1/4 gallons of white paint in his truck and another 3/6 gallons of white paint in a storage room.

How many more gallons of white paint does the painter need?

Correct answer:

x =  2 ³⁄₄ = 11/4 gal

Step-by-step explanation:

$$\begin{gathered} a=4\frac{1}{2}=4+\frac{1}{2}=\frac{4\cdot 2+1}{2}=\frac{8+1}{2}=\frac{9}{2}=4.5\text{gal} \\ b=1\frac{1}{4}=1+\frac{1}{4}=\frac{1\cdot 4+1}{4}=\frac{4+1}{4}=\frac{5}{4}=1.25\text{gal} \\ c=\frac{3}{6}=\frac{1}{2}=0.5\text{gal} \\ x=a-b-c=\frac{9}{2}-\frac{5}{4}-\frac{1}{2}=\frac{18}{4}-\frac{5}{4}-\frac{2}{4}=\frac{18-5-2}{4}=\frac{11}{4}=\frac{11}{4}\text{gal}=2\frac{3}{4}\text{gal}=2.75\text{gal} \end{gathered}$$

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