x^2 - 1 = 80
=> x^2 = 80 + 1
=> x^2 =81
=> x^2 =9^2
=> x = 9
Vậy x = 9
x2 - 1 = 80
x2 = 80 + 1
x2 = 81
\(\Rightarrow\)x = 9
\(x^2-1=80\)
\(x^2=80+1\)
\(x^2=81\)
\(x^2=9^2\)
\(=>x=9\)
Vậy \(x=9\)
x ^ 2 - 1 = 80
x ^ 2 = 80 + 1
x ^ 2 = 81
x ^ 2 = 9^2
= > x = 9
Vậy x = 9
K mk nha
Mk nhanh nhất
x2 - 1 = 80 => x2 = 80 + 1
=> x2 = 81 = 92 => x = 9
Vậy x = 9
\(x^2-1=80\)
\(\Rightarrow\)\(x^2=80+1\)
\(\Rightarrow\)\(x^2=81\)
\(\Rightarrow\) \(x=9\)
Tk mk mk nhé!Chắc chắn 100%!