Math · Week 3
Slope-intercept form, graphing lines, and checking solutions.
A linear equation graphs as a straight line. Slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept.
Slope is rise over run: m = (y2 − y1) / (x2 − x1). A positive slope rises left to right; a negative slope falls.
To graph, plot b on the y-axis, then use the slope to find a second point. Check by substituting a point back into the equation.
Parallel lines share a slope. Perpendicular lines have slopes that are negative reciprocals (m and −1/m).