# Step-by-step Solution

## Solve the product (a+3b)(a-3b)

Go
1
2
3
4
5
6
7
8
9
0
x
y
(◻)
◻/◻
2

e
π
ln
log
lim
d/dx
d/dx
>
<
>=
<=
sin
cos
tan
cot
sec
csc

asin
acos
atan
acot
asec
acsc

sinh
cosh
tanh
coth
sech
csch

asinh
acosh
atanh
acoth
asech
acsch

### Videos

$a^2-9b^2$

## Step-by-step explanation

Problem to solve:

$\left(a+3b\right)\left(a-3b\right)$
1

The sum of two terms multiplied by their difference is equal to the square of the first term minus the square of the second term. In other words: $(a+b)(a-b)=a^2-b^2$, where:

• The first term ($a$) is $a$.
• The second term ($b$) is $3b$.
Then:

$a^2-\left(3b\right)^2$
2

The power of a product is equal to the product of it's factors raised to the same power

$a^2-9b^2$

$a^2-9b^2$
$\left(a+3b\right)\left(a-3b\right)$