How to answer this one-?

45

Step-by-step explanation:

let x be the missing number:  x ÷ 3 - 6 = 9

add 6 to both sides:                     x ÷ 3 = 15

multiply both sides by 3:                   x = 45

Therefore,   45 ÷ 3 - 6 = 9

from the figure we get,

the x axis shows   the months and,

the y-axis shows the number of satisfied customer.

each line or each cell in upward direction (y-axis) shows 500.

the appropriate scale for the y - axis is: -

a = 2000 customers

b = 4000 customers

c = 6000 customers

d = 8000 customers

e = 10000 customers

f = 12000 customers

g = 14000 customers