Question

A number decreased by 18 is equal to the product of the number and 7.

Answer 1

----------------------------------------------------------------
Define x:
----------------------------------------------------------------
Let the number be x 

----------------------------------------------------------------
Construct Equation :
----------------------------------------------------------------
x- 18 = 7x

----------------------------------------------------------------
Take away x from both sides :
----------------------------------------------------------------
-18 = 7x - x

----------------------------------------------------------------
Combine like terms :
----------------------------------------------------------------
-18 = 6x

----------------------------------------------------------------
Switch sides :
----------------------------------------------------------------
6x = -18

----------------------------------------------------------------
Divide by 6 on both sides :
----------------------------------------------------------------
x = -3

----------------------------------------------------------------
Answer; The number is -3.
----------------------------------------------------------------

Answer 2

Hi there! The answer is x = - 3

A number decreases by 18 can be written as
$x - 18$

The product of the number and 7 can be written as
$7 \times x = 7x$

We get the following equation
$x - 18 = 7x$

Now subtract x from both sides.
$- 18 = 6x$

Switch sides
$6x = - 18$

Divide both sides by 6.
$x = - 18 \div 6 = - 3$

Therefore, the answer is x = -3