Slope-intercept form — Grade 8 Math, what it means and where it is taught
y = mx + b, with m the slope and b the y-intercept.
Taught in Grade 8 Math.
Where it is taught
What it rests on
Work through these first if this one does not settle.
- y-intercept — The output when x = 0 — where the line crosses the vertical axis.
- Slope — How much y changes for each 1 that x increases.
Practise this idea
4 questions in the course bank use Slope-intercept form, in Linear Functions & y = mx + b, Slope & the Forms of a Line.
Problem 1
Write 3x + y = 10 in slope-intercept form.
Worked answer
y = -3x + 10
Subtract 3x
y = -3x + 10
Note the slope is negative
Problem 2
Write 4x + 2y = 14 in slope-intercept form.
Worked answer
y = -2x + 7
2y = -4x + 14
y = -2x + 7
Problem 3
Write y - 4 = 2(x - 1) in slope-intercept form.
Worked answer
y = 2x + 2
y - 4 = 2x - 2
y = 2x + 2
Problem 4
Write the equation of the line with slope -2 through (-3, 8), in slope-intercept form.
Worked answer
y = -2x + 2
y - 8 = -2(x + 3)
y - 8 = -2x - 6
y = -2x + 2