A new cell phone costs $85, and the sales tax is 9%. What is the amount of the sales tax?A new cell phone costs $85, and the sales tax is 9%. What is the amount of the sales tax?A new cell phone costs $85, and the sales tax is 9%. What is the amount of the sales tax?

Step-by-step explanation:

Sales tax = $7.65

Explanation:

To find the sales tax, you would find 9% of $85

$85×9÷100 (You can reduce 85 and 100 because they have a common factor of 5)

$17×9÷20 (Multiply 9×17)

153÷20 = $7.65

step-by-step explanation:

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1