If 2a+ 2/a =4, what is the value of 2a^2− 2/a^2 ?

2 answers

2a+2/a=4
a+1/a=2
a^2+1=2a
a^2-2a+1=0
(a-1)^2=0
a=1
2(1^2+(2/(1)^2)=4
thanks