Finding the Equation of a Straight-Line Graph (VCE SSCE General Mathematics): Flashcards

$y = a + bx$

y-intercept (where line crosses y-axis at $x = 0$)

Slope/gradient (steepness of line)

ext{slope} = rac{ ext{rise}}{ ext{run}}

rac{y_2 - y_1}{x_2 - x_1}

When y-intercept is visible on graph

When y-intercept not visible or in all situations

Only works when $x = 0$ (y-axis) is visible on graph

Calculate slope $b$ using two points

Substitute other point's coordinates and check y-value matches