4 years old is the answer i think
Answer:
$690
Step-by-step explanation:
The amount she makes in a week=her weekly salary + the commission on sales.
Amount=330 + 7.5% of 4800.
Amount = 330+ 360=690.
The she would make if she sold $4,800 of merchandise is $690.
Cross multiplication!

=

7 × 24 = 8x
168 = 8x
Divide both sides by 8 to isolate x

=

8 and 8 cancels out
21 = x
The average rate of change formula is 
(-2-5)/(6-(-1))=-1