Expand.
If necessary, combine like terms.
(
3
x
+
7
)
(
3
x
−
7
)
=
(3x+7)(3x−7)=left parenthesis, 3, x, plus, 7, right parenthesis, left parenthesis, 3, x, minus, 7, right parenthesis, equals

9x^2-49

Step-by-step explanation: using pattern (a+b)(a-b)=a^2-b^2

(3x+7)(3x-7)=(3x)^2-7^2

=9x^2-49

168

step-by-step explanation:

first off, we know that he drove 3.5 hours at a rate of 48 mph.

knowing that, we want to see how many miles he drove all-together.

in this case, we can just multiply 48 by 3.5.

48 * 3.5 = 168