Kx+9=7
Kx=-2 (subtract 9 from both sides)
X=-2/k (divide k from both sides.
48.5 for all the rubber stamps
The answer should be 390=60s, assuming s is the number of shelves he would need.
By the way, if you want the answer using this formula:
390=60s
390/60=s
6.5=s
s=6.5
Answer: A
Step-by-step explanation: