<PRE><B>Question 896943</B>
Let A and B represent the numbers.
A + B = 70
3A -10 = B
Substitute the known value of B in the bottom equation into the top
A + B = 70
A + (3A-10) = 70
4A - 10 = 80
Add 10 to each side
4A = 80
Divide each side by 4
A = 20
If A is 20 and the two numbers together are 70, then B is 50 -- which is 10 less than 3 times 20.</PRE>