Question

A number decreased by 12 is 24.

Answer 1

A number decreased by 12 is 24...
n - 12 = 24
n = 24 + 12
n = 36 <== ur number

Answer 2

A number decreased by 12 is 24.
(by looking at your question, we can see that 'decreased by 12' =  subtract (-) 12)

We can write this as the equation n - 12 = 24, in which n = the number.

Now let's solve for n by using algebraic properties.

        n - 12 = 24
n - 12 + 12 = 24 + 12   (add 12 to both sides to isolate n)
               n = 24 + 12   (the -12 and +12 cancel to 0 on the left side)
               n = 36           (simplify, add 24 and 12)

Therefore the number is 36.