Four times the difference of 4 and a number amounts to 40. What is the number

Answer 1

Use "x" for the number.

Translating from english to the expression:

"Four times the difference of 4 and a number "----> 4 (4 - x)

"amounts to 40" ----> = 40

Put it together: 4 (4 - x) = 40

Solve this for x

Note an ambiguity:

"Four times the difference of 4 and a number " could also mean 4 (x - 4). Does this give you a different answer?

Answer 2

Let the number we are looking for be "X". In this case we are looking for this number which happens to be 4 plus the number "X" times 4. When we calculate this it must be equal to 40. So we set this up as an algebraic equation with one variable; that being "X".

It will look like this:

4 ( X - 4) = 40

Distribute the 4 across the parenthesis and we get

:

4X-16 = 40

Add 16 to both sides and we get::

4X = 56

Isolate the "X" by dividing 4 from both sides and we get:

X = 14

Now, lets plug 14 into the original equation and see if this is the correct answer:

4(14-4) = 40 so the answer is correct