Question

Un numero mas su doble es igual a su mitad mas quince ¿cual es el numero ?

Answer 1

For this case we have:

"One number plus its double equals its half plus fifteen, what is the number?"

x: Let the variable that represents the unknown number

According to the statement we have:

"One number plus its double" is represented as:
`x + 2x`

"Its half plus fifteen" is represented as:
`\frac {x} {2} +15`

Then we have the following expression:

`x + 2x = \frac {x} {2} +15`

We solve the equation:

`3x = \frac {x} {2} +15\\3x- \frac {x} {2} = 15\\\frac {6x-x} {2} = 15\\\frac {5} {2} x = 15\\5x = 30\\x = \frac {30} {5}\\x = 6`

So the number is 6

Answer:

`x = 6`