Explanation:
We will use 'x' as the number.
You convert the problem to an equation.
142+x=64+3(x)
Then you subtract 142.
142+x=64+3(x)
-142 -142
x=-78+3(x)
Now you subract 3x.
x=-78+3x
-3x -3x
-2x=-78
Finally, you divide.
-2x=-78
/-2 /-2
x=36
Hope it helps!