3) a number divided by three is nine more than the number.

Number is x =  -13.5

Step-by-step explanation:

Let the number is x

Given condition:

number divided by three is nine more than the number.

This can be written as:

x/3 = 9 + x

Taking x sides at left of equal will make the signs opposite

x/3 - x = 9

Taking denominators of both terms same (3)

x/3 - x* 3/3 = 9

(x- 3x)/ 3 = 9

-2x/3 =9

Multiplying both sides by -3/2

x = 9*(-3/2)

x = -27/2

x= -13.5

Proof:

Given condition is:

x/3 = 9 + x

Putting value of x

-13.5/3 = 9 + (-13.5)

-4.5 = -4.5

I hope it will help you!

nswer: a   y-axis

step-by-step explanation: