Solve the following puzzle:
'The sum of the ages of two brothers is 21. The sum of the squares of their ages is 233.
What are the two ages?'
Not sure is it's right, but so far i have
a + b = 21
b = 21 - a
a2 + b2 = 233
a2 + (21 - a)2 = 233
a2 + 441 - a2 = 233 <--- not sure if that it right? stuck here.