Question

4. What is the equation of a line with a slope of 5 that passes through the point (4,2) ? Express this equation in all three forms: point-slope, slope-intercept, and standard.

Answer 1

Incase you did not know, f(x) is a way of writing equations, for lines, if you do not know what the equation is.

2 = f(4)
f(x) = 5x-c
f(4) = 20-c
c = 20-2 = 18
f(x) = 5x-18

thus...
y = 5x-18

also...
the y intercept is -18

Answer 2

slope = 5
y = mx + b
2 =5(4) + b
b = 2 - 20
b = -18


point-slope equation
y - 2 = 5(x -4)

slope-intercept equation
y = 5x - 18

standard form
5x - y = 18