Bread black white

They sold 452 loaves of bread in the store. They sold three times more black bread than white bread.
How much white and black bread did they sell in the store?

Final Answer:

b =  113
c =  339

Step-by-step explanation:

$$\begin{gathered} b+c=452 \\ c=3\cdot b \\ b+c=452 \\ 3b-c=0 \\ Pivot:Row1\leftrightarrow Row2 \\ Row2-\frac{1}{3}\cdot Row1\to Row2 \\ 1.33c=452 \\ c=\frac{452}{1.33333333}=339 \\ b=\frac{0+c}{3}=\frac{0+339}{3}=113 \\ b=113 \\ c=339 \end{gathered}$$

Try another example