Question 143931
Let x=the other other number
Then 3x=the first number

Now we are told that:
 x+3x=164 or
4x=164  divide both sides by 4
x=41----------------------------the other number
3x=3*41=123------------------------the first number

CK
41+123=164
164=164

Another way:

Let x=the first number
And let y=the second number

x+y=164-----------------------eq1

x=3y-----------------------------eq2

Substitute x=3y from eq2 into eq1 and we get:

3y+y=164
4y=164
y=41-------------the second number
substitute y=41 into eq2
x=3y=3*41=123-------the first number


Hope this helps---ptaylor