Answer:
![4c+6a\leq120\\\\4c+4a\leq100](https://img.qammunity.org/2020/formulas/mathematics/high-school/9jlna6yovdw88432tmbvhz6jwun7ti7mlg.png)
Explanation:
Let c represents child bikes and a represents adult bikes.
Given : Each child bike requires 4 hours to build and 4 hours to test. Each adult bike requires 6 hours to build and 4 hours to test.
With the number of workers, the company is able to have up to 120 hours of building time and 100 hours of testing time for a week.
Then, the required system of inequality :-
![4c+6a\leq120----(1)\\\\4c+4a\leq100-----(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/8nw3uzzp649809m0364phm90ymwdvoa7k2.png)
If company make 10 child bikes and 12 adult bikes in the week.
Then Put c=10 and a=12 bikes in (1) and (2).
⇒Bike order meets the restrictions
⇒Bike order meets the restrictions
Hence, the system of inequality best explains whether the company can build 10 child bikes and 12 adult bikes in the week.
![4c+6a\leq120\\\\4c+4a\leq100](https://img.qammunity.org/2020/formulas/mathematics/high-school/9jlna6yovdw88432tmbvhz6jwun7ti7mlg.png)