Sai Ane

Algebra 2

Tutorial

To find point-slope form (Basic Equation)

y-y1 = m(x-x1)

• The point-slope form relies on the point which is used
• If you know the slope and a point on the line, use this formula to write an equation.
• Answer should be in y=mx + b format

Example Problems

#1. Find the equation of the line that passes through (1, 4) and a slope 2/3.

First Step, write formula: y-y1 = m(x-x1)

Second Step, plug in numbers to matching variables: y-4 = 2/3(x-1)

Third Step: solve for (Y): y-4 = 2/3(x-1)

Y - 4 = 2/3x – 2/3

y = 2/3x – 2/3 + 4

y = 2/3x – 2/3 + 12/3

y = 2/3x – 10/3

#2. Find the equation of the line that passes through points (1, 1) & (-2,-2)

First Step, find slope: y2-y1 -2-1 = 1

x2-x1 -2-1

Second step, plug in point slope equation, and pick any point: y-y1 = m(x-x1)

Y-1 = m(x-x1)

Y-1 = x-1

y = x-1+1

y = x+0

y = x

Practice Problems

• Write an equation of the line that passes through.

1) (5, 2) slope 1/3

2) (2, 3) & (4, 4)

3) (1, 4) slope ¾

4) (7, 6) & (4, 4)