parallell and perpendicular lines
posted by luckybee .
please check my homework
given P(7,2) and the line y + 3x=7 find the equation for the line
parallel line: y+3x+7
y=3(x7) +7
y2=3x+21+7
y=3x+28+2
y=3x+30
perpendicular line:
y2=1/3(x7) +7
y2=1/3x7/3 +21/3
y2==1/3x + 14
y=1/3x + 14 +2
y=1/3x +16

parallell and perpendicular lines 
Reiny
Here is a neat way to do these question in a quicker way
You should have learned that for a straight line equation in the form
Ax + By = C, the slope of the line is A/B
so for 3x+y = 7 , a parallel line will differ only in the C value
so new equation is
3x + y = C
plug in the point (7,2)
21 + 2 = C = 23
so new equation: 3x + y = 23 or y = 3x  23
notice the given point does not even satisfy your final equation.
Your error is in the 2nd line, should be
y = 3(x7) + 2
For the perpendicular short cut way:
slope of given equation is 3
so slope of perpendicular line is +1/3
new equation:
x  3y = C, plug in the point (7,2)
7  6 = C = 1
x  3y = 1 or y = (1/3)x  1/3
again, you made the error in the 2nd line, it should say
y2 = (1/3)(x7)
then 3y  6 = x7
x  3y = 1 , the same result as mine
Respond to this Question
Similar Questions

Math 10
1 more question.... how would I make this equation perpendicular? 
Geometry
Prove that the tangents to a circle at the endpoints of a diameter are parallel. State what is given, what is to be proved, and your plan of proof. Then write a twocolumn proof. Hint draw a DIAGRAM with the points labeled. Can some … 
Writing this equation
how do I write the equation of a line perpendicular to the line 6x – 3y=10 and containing the point (6, 2). The line you are given can have its equation rewritten im y = mx + b as: y = 2x  10/3 That tells you that is slope is m … 
math
parallel and perpendicular lines Determine an equation of each of the following lines . *the line perpendicular to y4=0 and passing through the point (1,6) ** the line perpendicular to 3x12y+16=0 and having the same yintercept … 
math
I need help with "write in equation in slopeintercept form for the line that is parallel to to the given line line and and that passes through the given point. y=1/2x=5;(4,3) How do you find a line that is perpendicular. Please and … 
math
19. Which statement describes the relationship between the line graphs of the equations below? 
precalc
write a linear equation to fit each situation or description. 1) the line through (2,4) parallel to the x axis. 2) the line through (2,4) perpendicular to the x axis. 3) the line through (3,1) perpendicular to y=4x3. 4) the line through … 
math2
I was solving a problem. In It r have been given that two lines are perpendicular to each other The equation of one line 2x3y+4=0 Now i have to find the equation of another line We can find it by finding the slope of the abovementioned … 
Math
Draw: 1)Line AB parallel to Ray CD perpendicular to line EF 2)Line GH perpendicular to line IJ,Line GH perpendicular to Line KL and Line IJ perpendicular to Line KL 3)Line Segment BC coplanar to Line TS 
Math
Draw: 1)Line AB parallel to Ray CD perpendicular to line EF 2)Line GH perpendicular to line IJ,Line GH perpendicular to Line KL and Line IJ perpendicular to Line KL 3)Line Segment BC coplanar to Line TS