Find the number?

First we ll write an equation using x as the unknown number.

1) 12 subtracted from 7 times a number
> 7x - 12

2) is equal to 5 times the sum of the number and 2
> = 5 ( x + 2)

3) 7x - 12 = 5(x + 2)

4) Solve
> 7x - 12 = 5(x + 2)
> 7x - 12 = 5x + 10
> 7x - 5x = 10 + 12
> 2x = 22
> x = 11


(In case you don t know how to work out the equation here is the answer worded:

> 7x - 12 = 5(x+2)
Expand the left side by multiplying what s in the brackets by what is outside
> 5(x + 2)
> 5*x + 5*2
> 5x + 10

Place it back in the equation
> 7x - 12 = 5x + 10

Place all known and unknown on different sides

a) bring all x values to the left, if the cross the equal sign the value changes ( - to +) or (+ to -)
> 7x - 5x - 12 = 10

b) bring all numbers to the right
> 7x - 5x = 10 + 12

> 2x = 22

Divide the number 22 by 2 because 2x is the unknown.

> x = 22/2
> x = 11

x = 11

7x - 12 = 5 [ x + 2 ]
7x - 12 = 5x + 10
2x = 22
x = 11______is the number

11

7x -12=5(x+2)
7x -12=5x+10
2x=22; x=11