Question

Which equation represents a linear function?

Answer 1

y - 5 = x - 20

Explanation:

The equation of a linear function in

slope-intercept form:
`y=mx+b`

point-slope form:
`y-y_1=m(x-x_1)`

standard form:
`Ax+By=C`

general form:
`Ax+By+C=0`

1.

y(x - 1) = 9

xy - y = 9 NO

2.

y - 5 = x(-x + 2)

y - 5 = -x² + 2x NO

3.

y(y - 1) = x + 25

y² - y = x + 25 NO

4.

y - 5 = x - 20

y - 5 = 1(x - 20) YES (it's a point-slope form)