Question

find a number such that when it is added to two thirds of itself the result is 70

Answer 1

let the number be x 
x+2x/3 =45
multiply by 3
3x+2x=3*45 
5x=3*45
x= 3*45/5 
x=27

Answer 2

Okay so, first you need to put this into an equation so:

x+2/3x=70

You want to have fractions with the SAME denominators so make the fractions have 6 as a denominator:

[tex] \frac{x}{1} + \frac{2x}{3} = \frac{70}{1} [/tex]

So,

$\frac{6x}{6} + \frac{4x}{6} = \frac{420}{6}$

So simplifying this down we get:

$\frac{10x}{6} = \frac{420}{6}$

Now, we multiply to get rid of the denominators so:

60x = 2520
x     = 42

We can also check,

42/3 = 14
14x2=28

42+28=70