Answer:
(-5/2,-1/4)
Step-by-step explanation:
Answer:
β = arccos((a^2 + c^2 - b^2)/(2·a·c))
β = arccos((3^2 + 7^2 - 5^2)/(2·3·7)) = 38.21°
Answer:
250 minutes of calling will cost same using both plans.
$53
Step-by-step explanation:
Please consider the complete question.
A phone company offers two monthly plans. Plan A costs $23 plus an additional $0.12 for each minute of calls. Plan B costs $18 plus an additional $0.14 of each minute of calls. For what amount of calling do the two plans cost the same? What is the cost when the two plans cost the same?
Let x represent the number of call minutes.
The total cost of calling for x minutes using plan A would be cost of x minutes plus fixed charge that is
.
The total cost of calling for x minutes using plan B would be cost of x minutes plus fixed charge that is
.
To find the number of minutes for which both plans will have same cost, we will equate total cost of x minutes for both plans and solve for x.







Therefore, calling for 250 minutes will cost same using both plans.
Upon substituting
in expression
, we will get:

Therefore, the cost will be $53, when the two plans cost the same.
Answer:
a = 15
Step-by-step explanation: