Really simple math time.

Ok I'm just doing factorisation of a quardratic expression of the form ax²+bx+c

And I've come across these two which I can't figure out what I'm supposed to do.

Factorise, where possible

7x²+47x+7

And

3x²+7xy+3y²

The book I have doesn't even have the answers for these in the back.

3x²+7xy+3y²

so
3x² = a²x² -> a² = 3
3y² = b²y² -> b² = 3
7xy = 2abxy -> 2ab = 7

that's an impossible system, >>11, cause ab would be either 3 or -3, and in both cases, it's impossible for 6 = 7 or -6 = 7.

fail

unless you do it so that 7xy = 6xy + xy and then it'd be
3x² + 7xy + 3y² = 3(x+y)² + xy