You are researching different phone companies. Company one is going to charge you $10 per
line plus a $40 data charge. Company 2 does not have a data charge and will charge you $20 per
line. How many lines would result in the two companies costing the same?

4 lines

Step-by-step explanation:

40 + 10x = 20x

40 = 10x

4=x

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)