Solve the system of equations to find x,y,z (hint let d=x2 e=y2 and d=z2 . Find d e and f first) !!where ever you see 2 it's supposed to be a squared sign.

I've seen questions answered similar to this but I don't understand how to get z^2 and y^2

X2+y2+z2=9
3x2-y2-z2=7
Y2+2z2 =6

This has popped up two or three times in the last few days. Don't know why it doesn't appear in the list of related questions. Try here:

https://www.jiskha.com/display.cgi?id=1506885649