Question

A straight line passes through points (1, 15) and(5, 3) What isthe equation of the line?Select one:A) y = - 3x + 18B) y = – 7x + 18C) y = 2x + 18D) y = 3x + 18

Answer 1

Points (1,15) and (5,3)

Find the slope (m)

`m=(y2-y1)/(x2-x1)`

where:

(x1,y1) = (1,15)

(x2,y2) = (5,3)

Replacing:

`m=(3-15)/(5-1)=(-12)/(4)=-3`

the function has a slope m= -3

slope intercept form:

y=mx+b

Where

m= slope

so, the correct function is

y=-3x+18 (A)