Answer:
9 weeks.
Explanation:
We need to find about how many weeks (w) it will take before Factory B has printed as many books (b) as Factory A.
In other words we need to find the value of week (w) when number of books from both factories are equal.
so set both equation equal
![50w+650=100w+200](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kca022f05e96s4i9gi8un6j61gxaqj7bgy.png)
![50w-100w=200-650](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dne074gcumtzuf6e6q87hxnc2npafk6q4n.png)
![-50w=-450](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g10szhx45kaaczjxa5kf3c6cz7yyyd9dk4.png)
![w=(-450)/(-50)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lo553tpnt0x37o8o7zzilicnvov85semkp.png)
![w=9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gnvdoubvgwe9ns2md1uqky95j1lq7xrftf.png)
Hence final answer is 9 weeks.