$3.15 would be the cost, after the mark up is added.
Answer:
x=-8 OR X=2
Step-by-step explanation:
X²+6X-6=10
X²+6X-16=0
X²+8X-2X-16
X(X+8)-2(X+8)
X+8=0 X-2=0
X=-8 OR X=2
Answer:
The costs of the plan are $0.15 per minute and a monthly fee of $39
Step-by-step explanation:
Let
x ----> the number of minutes used
y ----> is the total cost
step 1
Find the slope of the linear equation
The formula to calculate the slope between two points is equal to

we have the ordered pairs
(100,54) and (660, 138)
substitute


step 2
Find the equation of the line in point slope form

we have

substitute

step 3
Convert to slope intercept form
Isolate the variable y

therefore
The costs of the plan are $0.15 per minute and a monthly fee of $39
You need to use the cosine for this and this is how you do it.