Explanation:
=
−
±
2
−
4
√
2
x=2a−b±b2−4ac
Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.
9
2
−
8
1
=
0
9x^{2}-81=0
9x2−81=0
=
9
a=
a=9
=
0
b={\color{#e8710a}{0}}
b=0
=
−
8
1
c={\color{#129eaf}{-81}}
c=−81
=
−
0
±
0
2
−
4
⋅
9
(
−
8
1
)
√
2
⋅
9
x=2⋅9−0±02−4⋅9(−81)