Write the equation of the line that passes through the points (1, 7) and (5, 15) using function notation. a) y = 2x + 5 b) y = 4x + 8 c) f(x) = 2x + 5 d) f(x) = 4x + 8

c) f(x) = 2x + 5

Step-by-step explanation:

slope  = (y2-y1)/ (x2-x1)

 m = (15-7)/(5-1)

  m = 8/4

m=2

point slope form for an equation is

y-y1 = m(x-x1)

y-7 = 2 (x-1)

distribute

y-7 = 2x-2

add 7 to each side

y-7+7 = 2x-2+7

y = 2x +5

it asks for the equation in function notation

f(x) = 2x+5

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

the slope of the line is 60

one point on the line is (40,10)

step-by-step explanation:

in the equation outside the parenthesis the equation always tells you the slope. in this case it is 60.

in the parenthesis is also says 40 which is x because it is near the x and 10 is y because it is near y.