Mary purchased a prepaid phone card for $30.00. Calls cost 20 cents a minute using this card. The credit, C (in dollars), left on the card after it is used for x
minutes of calls is given by the following.
C = 30.00 -0.20x
How much credit is left on the card after Mary uses it for 50 minutes of calls?

$40 is left on the card after Mary uses it for 50 minutes of calls.

Step-by-step explanation:

Let x represent the number of minutes of calls made

The credit, C (in dollars), left on the card after it is used for x

minutes of calls is given by the expression,

C = 30.00 -0.20x

After Mary used the credit for 50 minutes of calls, the amount of credit that would be left on the card is

C = 30.00 - 0.20 × 50

C = 30 + 10

C = $40

neither i nor ii 56 / 4.9 = 11.91489362 and 82 / (11+5) =5.125 so i is wrong

ii. (24/8+2) times 3 = 15 and (42+9)/2 =25.5

step-by-step explanation:

56

answer: evaluate the objective function at each vertex to determine which - and -values, if any, maximize or minimize the function. example: find the minimum value and maximum value of the objective function f ( x , y ) = 4 x + 5 y , subject to the following constraints