Answer
For company A and B we have $A: \$ 590,000; B: \$ 595,562$
Work Step by Step
Here, we have $a_1= 20,000$ and $b_1= 20,000$
We know that $a_n=a_1+(n-1)d$
Plug $d=1000$
And $r=1+0.04=1.04$
$a_{20}=20,000+(20-1) \times (1000)=39,000$
$S_{20}=\dfrac{20 \times (20,000+39000)}{2}=590,000$
The sum $T_n$ of the first n terms of the sequence $b_n$ can be found as:
$T_n=\dfrac{20,000(1-1.04^{20})}{1-1.04} \approx 595,562$
Hence, for company A and B we have $A: \$ 590,000; B: \$ 595,562$
