Question

Manoj and Tamar are arguing about a number trick they heard.

Tamar tells Andrew to think of a number, multiply it by five and

subtract three from the result. Then Manoj tells Andrew to think

of a number, add five and multiply the result by three. Andrew

says that whichever way he does the trick he gets the same

answer.

a. What was the number Andrew started with?

b. What was the result Andrew got both times?

c. Name another set of steps that would have resulted in the

same answer if Andrew started with the same nu

Answer 1

a . Andrew's started with number 9

b. 42

c. 4x + 6 = (x+12)*2

Explanation:

Let the Andrew's number is x

• Tamar tells Andrew to think of a number, multiply it by five and

subtract three from the result

5x - 3

• Manoj tells Andrew to think of a number, add five and multiply the result by three.

(x +5)*3

as he was getting the same answer so both the numbers will be equal

5x -3 = (x+5)*3

5x - 3 = 3x + 15

2x = 18

x = 9

a. Andrew's started with number 9

b. (1) 5x- 3 = 5*9 - 3

= 42

(2) (x + 5)*3

= 14*3 = 42

c. Think of a number, then multiply it with 4 then add 6 in it

Think of a number add 12 in it then then double it.

4x + 6 = (x+12)*2

x = 9