Equations of Linear Relations Lesson #3

Writing Equations using y – y1 = m(x – x1)

 

  • To determine the equation of a line in future math courses, the point – slope equation, y – y1 = m(x – x1), is used more frequently than the slope – y – intercept equation, y = mx + b.

 

Q. The slope of a line end a point on the line are given. Determine the equation of the line in slope y-intercept form.

A. y= 2/3x – 12

 

Equations of Linear Relations Lesson #4

The General Form Equation Ax + By + C =0

 

  • Given the equation of a line in general form, Ax + By +  C =0, the slope and y – intercept can be found by converting the equation into slope y – intercept form, y = mx + b.

 

Ex) 2x – 3y + 12 =0

2x : always positive

2x – 3y + 12 : all integer values

 

Q. Determine the equation of a line which is perpendicular to the line 2x – 6y + 6 =0 and has same y-intercept.

A. 3x + y – 1 =0