A phone company offers two monthly plans. Plan A costs $8 plus an additional $0.09 for each minute of calls. plan B cost $16 plus an additional $0.07 for each minute of calls. a. For what amount of calling do the two plans cost the same? minutes

b. What is the cost when the two plans cost the same? $​

72

Plan A = 30 +0.15x

Plan B = 16 +0.20x

30+0.15x = 16+0.20x

subtract 16 from each side

14 +0.15x = 0.20x

subtract 0.15x from each side

14=0.05x

x = 14/0.05 = 280 minutes

280*0.15 = 42 +30 = $72

280 * 0.20 = 56 +16 = 72

280 minutes and cost $72 each

Step-by-step explanation:

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below:

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)