If (P_b)*(P_b)=31_b, where P and b represent two distinct digits 0-9 and P is one less than b, what is the value of base b?
So I have ((b-1)_b)^2=31_b
how do I do this?! please explain. :)
P=b−1(b−1)2=31b=3b+1b2−2b+1=3b+1b2=5bb=5 (or 0, but 0 is not a valid base)b=5, P=4(45)2=1610=315