Let the amount invested at 4% be = x
Let the amount invested at 3% be = y
Given is:
or
.... (1)
As, total income for the two investments is $194, so equation is:
....(2)
Putting value of x from (1) in (2)




And x=5200-y

Hence, money invested at 4% is $3800 and money invested at 3% is $1400
The answer is C, from where the end lines go down to on the graph
Same slopes, different constant, so parallel lines.
Answer: ... parallel because their slopes are equal. Last choice.