We will solve as follows:
*We have the equations:
![9.50A+27.00B=4000](https://img.qammunity.org/2023/formulas/mathematics/college/yxin34rbixqi2dygiqkq2p4nxdi76l7s0i.png)
&
![A+B=200](https://img.qammunity.org/2023/formulas/mathematics/college/6smrjm3y1sv2w7d90mk5pena66goslu9ko.png)
We solve then for the second equation [Either for A or B], that is:
![A=200-B](https://img.qammunity.org/2023/formulas/mathematics/college/r5fg4xwfwwlhd59icgk5s5xl2hwcstf3w7.png)
Now, we replace in the first equation and solve for B:
![9.50(200-B)+27.00B=400\Rightarrow1900-9.50B+27.00B=4000](https://img.qammunity.org/2023/formulas/mathematics/college/kx9rdsriq6697aoma4cfkt00bnwjxirahw.png)
![=17.5B+1900=4000\Rightarrow17.5B=2100](https://img.qammunity.org/2023/formulas/mathematics/college/f9kk38s24tdrbuq7ksyhfyr8n8ygm1xrq8.png)
![\Rightarrow B=120](https://img.qammunity.org/2023/formulas/mathematics/college/kyd440coplgl5vyv2qu0ow84ub794mhkng.png)
Now, we replace the value of B in the second equation:
![A=200-(120)\Rightarrow A=80](https://img.qammunity.org/2023/formulas/mathematics/college/41vxm5kctl3c40uzqpeoh3mcj2f8774ytk.png)
So, the investor has 80 shares on stock A and 120 shares on stock B.