Line equation from two points
The question
Write the equation of the line through (1, 4) and (2, 6).
Write the equation of the line through (1, 4) and (2, 6)
slope = (6 − 4) ÷ (2 − 1)
2 ÷ 1=2
b = 4 − (2)(1)=2
y = 2x + 2
- Find the slope first: rise over run, (6 − 4) ÷ (2 − 1) = 2.
- Put a point back in to find b: b = y − mx = 4 − (2)(1) = 2.
- Write it as y = mx + b: y = 2x + 2.
How it works.
- 01
Find the slope first: rise over run, (6 − 4) ÷ (2 − 1) = 2.
- 02
Put a point back in to find b: b = y − mx = 4 − (2)(1) = 2.
- 03
Write it as y = mx + b: y = 2x + 2.