Reference
Practice
Premium
Log In
English
English ✔
Español
日本語
简体中文
繁體中文
\[(x-9)(x+9)\]
+
−
.
ln
>
<
×
÷
/
log
≥
≤
(
)
log
x
=
%
Choose Topic
Examples
"(x+1)/2+4=7"
"factor x^2+5x+6"
"integrate cos(x)^3"
More »
expand((x-9)(x+9))
expand (x-9)(x+9)
(x-9)(x+9)
1
Use
Difference of Squares
:
a
2
−
b
2
=
(
a
+
b
)
(
a
−
b
)
{a}^{2}-{b}^{2}=(a+b)(a-b)
a
2
−
b
2
=
(
a
+
b
)
(
a
−
b
)
.
x
2
−
9
2
{x}^{2}-{9}^{2}
x
2
−
9
2
2
Simplify
9
2
{9}^{2}
9
2
to
81
81
8
1
.
x
2
−
81
{x}^{2}-81
x
2
−
8
1
Done
x^2-81
Like this solution? Share it!
Copy Link
How can we make this solution more helpful?
English
Choose Topic
