Answer:
$51.70
Step-by-step explanation:
I don't know how to explain it actually so I am just going to do this...
y= 0.1(x + 20) +7
y=0.1x + 2 + 7
y=0.1x +9
y=0.1(427)+9
y=42.7+9
y=51.7
So, maybe the answer is $51.70.