2. • Given the line 2x – 3y = 9 and the point (4, –
1), find lines through the point that are
• (a) parallel to the given line and
• (b) perpendicular to it.
3.
4. • solve "2x – 3y = 9" for "y=", so that you can find the
reference slope:
• 2x – 3y = 9 –3y = –2x + 9 y = ( 2/3)x – 3
The reference slope from the reference line is m = 2/3
5. • Previous answer: slope m = 2/3
• y – (–1) = ( 2/3 )(x – 4) y + 1 = ( 2/3 ) x – 8/3 y = ( 2/3 ) x
– 8/3 – 3/3 y = ( 2/3 ) x – 11/3
6. Step 3: perpendicular line
• for the perpendicular slope; flip the slope and change the
sign.
• perpendicular slope is m = – 3/2
• point-slope form:y – (–1) = ( – 3/2 )(x – 4) y + 1 = ( – 3/2 ) x
+ 6 y = ( – 3/2 ) x + 5
• Full Solution =
7. Resource Slide
• http://www.purplemath.com/modules/strtlneq3.htm
• http://www.ixl.com/math/standards/california/algebra-1
• Butte County Regional Occupational Program. Career and Technical Education Online.
Chico, Calif.: Butte County Office of Education. http://www.cteonline.org (accessed October
2004).
• California State Board of Education. Content Standards. http://www.cde.ca.gov/be/st/ss/
index.asp
• California State Board of Education. Curriculum Frameworks. http://www.cde.ca.gov/be/st/fr/
index.asp
8. • (5.0) Students solve multistep problems, including word
problems, involving linear equations and linear inequalities in one
variable and provide justification for each step.
• (6.0) Students graph a linear equation and compute the x- and y-
• (8.0) Students understand the concepts of parallel lines and
perpendicular lines and how those slopes are related. Students
are able to find the equation of a line perpendicular to a given line
that passes through a given point.
• (10.0) Students add, subtract, multiply, and divide monomials and
polynomials. Students solve multistep problems, including word
problems, by using these techniques.
