Answer:
a = 12
Step-by-step explanation:

Convert element into fraction : 3= 3/1

Cross multiply

"if you break down a $1 bill, it is 4 quarters. If you add the 4 quarters to the other 3 then you will get the sum of 7."
Hope this helps!
Answer: 945
Step-by-step explanation:
this month = 450.
next month 450x10/100=45, 450+45= 495
450+495= 945
Answer:
f'(9) = 6
Step-by-step explanation:
f(x) = 6x+7
The derivative is
f'(x) = 6
Evaluated at x=9
f'(9) = 6
$132.55-($15*12)=$132.55-$180=$-47.45
So then he would have owed 47.45 dollars!