Question 65073
You don't.
You can't add {{{x^2+y^2}}}
Look what happens if you substitute numbers in:
{{{3^2+5^2}}}
{{{9+25}}}
{{{34}}} <--that's the actual answer, but if you did this
{{{3^2+5^2}}}
{{{8^2=64}}} <---you get the wrong answer.
Happy Calculating!!!