Question

If the sum of a number and five is doubled, the results is one less than the number.find the number

Answer 1

`-11`

Explanation:

Let the number be "x"

So,

Sum of the number and 5 is DOUBLED, the result would be ONE LESS THAN number, so we can write:

(x + 5)*2 = x - 1

See how we took the sum, added parenthesis and then DOUBLED it (LHS). And RHS is 1 less than number (x). Now we simply use distributive property [ a(b+c) = ab + ac ] to simplify and solve for x, the number. Shown below:

`(x + 5)*2 = x - 1\\2x+10=x-1\\2x-x=-1-10\\x=-11`

Thus,

the number is -11