perpendicular 2x+5y=10
⇥Let's solve in ℝ: 2x + 5y = 10
⇥ 5y = 10 -2x
⇥Solution obtained: y = 10 -2x5
The slope-intercept form is y = mx + b: the slope is -25 and the y-intercept is 2
No point is specified: find the family of perpendicular lines
m is the slope of the perpendicular line. The slopes of two perpendicular lines have product -1: -25·m = -1.
⇥Let's solve in ℝ: -25·m = -1
⇥ -2m5 = -1
⇥ -2m = -1·5
⇥ -2m = -5
⇥ 2m = 5
⇥Solution found: m = 52
The y-intercept b is an arbitrary real number
▶Perpendicular lines:   y = 5x2 + b