Manufacturing 28591

A furniture manufacturing company consumes 124 cubic meters of spruce and oak lumber per month. Spruce lumber consumes three times more than oak lumber. How much spruce and oak lumber does the company use per month?

Correct answer:

s =  93 m³
d =  31 m³

Step-by-step explanation:

$$\begin{gathered} s+d=124 \\ s=3d \\ s+d=124 \\ s=3\cdot d \\ d+s=124 \\ 3d-s=0 \\ Pivot:Row1\leftrightarrow Row2 \\ 3d-s=0 \\ d+s=124 \\ Row2-\frac{1}{3}\cdot Row1\to Row2 \\ 3d-s=0 \\ 1.33s=124 \\ s=\frac{124}{1.33333333}=93 \\ d=\frac{0+s}{3}=\frac{0+93}{3}=31 \\ d=31 \\ s=93=93{\text{m}}^3 \end{gathered}$$

Try another example