For what value of X must ABCD be a parallelogram?

Solution:

We know that:

This means that:

Step-by step calculations:

Simplify the RHS:

Subtract 13x both sides:

Divide -1 both sides:

i'm pretty sure it's 477,585,296, but perhaps my math is incorrect.

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