Answer: x
2
=
81
can be written as
x
2
−
81
=
0
by property ,
a
2
−
b
2
=
(
a
+
b
)
(
a
−
b
)
The expression becomes
x
2
−
(
9
)
2
=
0
(
x
−
9
)
(
x
+
9
)
=
0
equating each of the terms with zero we obtain the solution
x
−
9
=
0
and
x
+
9
=
0
the solutions are
x
=
9
or
x
=
−
9
Step-by-step explanation:
