Customers of a phone company can choose between two service plans for long distance calls. The first plan has a $28 monthly fee and charges an additional $0.09 for each minute of calls. The second plan has no monthly fee but charges $0.13 for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

700 Minutes

Step-by-step explanation:

For this problem, we need to write an expression that represents the cost per the amount of time used for each phone plan, and set the two expressions equal to each other to find how many minutes would be needed for the costs to be equal.

For the first phone plan, we have a base $28 and additional $0.09 per minute of call.  This can be expressed as:

28 + 0.09x                  Where x is the number of minutes used

For the second phone plan, we have a flat $0.13 per minute of call.  This can be expressed as:

0.13x                           Where x is the number of minutes used

To find how many minutes would be used to make the cost equal, we simply set these expressions as equivalent, and solve for x.

28 + 0.09x = 0.13x

28 + 0.09x + -0.09x = 0.13x + -0.09x

28 = 0.04x

28 = (1/25)x

28 * 25 = (1/25)x * 25

28 * 25 = x

700 = x

Thus, for the cost of these phone plans to be equal, you would have to use 700 minutes per month.

Cheers.

(2x + 16) + (x) = 180

step-by-step explanation:

given,

abcd is a quadrilateral inscribed in a circle

angle a is labeled x plus 16, (x + 16)

angle b is labeled x degrees, (x)

angle c is labeled 6x minus 4, (6x – 4)

angle d is labeled 2x plus 16, (2x + 16)

what equation can be used to solve for angle b?

we know that the sum of the opposite angles of a simple quadrilateral inscribed in a circle is 180 degrees.

angle b is opposite angle d

therefore, angle b + angle d = 180

(x) + (2x + 16) = 180 

same as (2x + 16) + (x) = 180

b

step-by-step explanation: