Samuel orders four DVDs from an online music store. Each DVD costs $9.99 He has 20% discount code, and sales tax is 6.75% What is the total cost of his order

$47.95

Step-by-step explanation:

$9.99 x 4 = $39.96 x 0.20 = $7.99

$39.96 + $7.99 = $47.95

a = 1

Step-by-step explanation:

One must simplify this expression, by distributing. In order to find a solution, where x has infinite solutions, one must make this equation an identity. That means that the equation will hold true, no matter what value of x is plugged in.

Distribute;

6x - 2 = 6x - 2a

Inverse operations;

6x - 2 = 6x - 2a

-6x        -6x

-2 = -2a

1 = a

For this equation to be true no matter what, a must equal 1.