Question

the sumof three positive numbers is 26.the second number is 3times as large as the first.if te sum of the squares of these numbers is least find the numbers

Answer 1

x+y+z = 26
y = 3x

You want minimal x^2+y^2+z^2, so check out a few possibilities:

x y z ∑*^2
1 3 22 488
2 6 18 332
3 9 14 208
...

I think you can figure it out.

Answer 2

that sucks