Answer:
35 more tax returns.
Explanation:
Let x represent number of required tax returns.
We have been given that a CA get paid $160 for each tax return he prepares and his goal is to earn 6240 preparing tax return.
Since CA has already prepared 4 tax returns, so amount earned from tax returns would be
.
The amount earned from preparing x tax returns would be
.
We can represent our given information in an equation as:
![160x+640=6240](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jfg6mcr0xx7bu3ew7n7ofbi9s8srjtmsmi.png)
![160x+640-640=6240-640](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b4qicbsellbfrl19itwpcpm1q5r9fe3vhl.png)
![160x=5600](https://img.qammunity.org/2020/formulas/mathematics/middle-school/he361n7pl8tzzzhw7qq9op4wps51hdsxq3.png)
![(160x)/(160)=(5600)/(160)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/rj79dnwgv0imzysoatzfzjzfjqhzjd3gd4.png)
![x=35](https://img.qammunity.org/2020/formulas/mathematics/middle-school/behvpftvyx7yzmq25vfxib6rqtd3uby11v.png)
Therefore, the CA must prepare 35 more tax returns in order to reach his goal.