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:

$x = 6$