a - 1/a =5
take squaring both side
(a - 1/a )^2 = (5)^2
a^2 +1/a^2 -2.a.1/a =25
a^2+1/a^2 -2 =25
a^2+1/a^2 =27 (answer)
Answer:
[tex]a^2+\frac{1}{a^2}=23[/tex]
Step-by-step explanation:
[tex]a+\frac{1}{a}=5\\squaring\\a^2+(\frac{1}{a})^2+2\times a \times \frac{1}{a}=5^2\\a^2+\frac{1}{a^2} +2=25\\a^2+\frac{1}{a^2}=25-2=23[/tex]
