Given:
Christopher has 20 video games and will buy 4 more each month
Peter has 92 video games and will sell 5 each month
Let the number of months required for them to have an equal number of video games be x
Hence:
![\begin{gathered} 20\text{ + 4}*\text{ x = 92 - 5}* x \\ 20\text{ + 4x = 92 -5x} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/tski743k61edwzg61tynkzkgl2bhd5j085.png)
Solving for x:
![\begin{gathered} \text{Collect like terms} \\ 4x\text{ + 5x = 92 - 20} \\ 9x\text{ = 72} \\ \text{Divide both sides by 9} \\ (9x)/(9)\text{ = }(72)/(9) \\ \text{x = 8} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/efr4j1eqhpxy3i4jun5cwat8br9yhxyu0j.png)
The number of video games they would both have is obtained by substitution
![\begin{gathered} =\text{ 20 + 4x} \\ =\text{ 20 + 4}*8 \\ =\text{ 20 + 32} \\ =\text{ 52} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/aey25p2d40q8j89wyjooib6idfrwz49eva.png)
Answer:
8 months , 52 video games