Answer two questions about Systems AAA and BBB: System AAA \text{\quad}start text, end text System BBB \begin{cases}x-7y=-3\\\\4
x+y=7\end{cases} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ x−7y=−3 4x+y=7 \begin{cases}4x+y=7\\\\x-7y=-3\end{cases} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ 4x+y=7 x−7y=−3 1) How can we get System BBB from System AAA?
That would be 40 books on each shelf. Hope that helped :) Here is the process: 2,160/ 9 stands = 240 books per stand 240 stands/ 6 shelves each = 40 books on each shelf.
