Need algebra help to write the equation of a line

Algebra
Tutor: None Selected Time limit: 1 Day

write the equation of a line the passes through the point (7,-2) and is perpendicular to the line x+3y=15

Nov 12th, 2015

Thank you for the opportunity to help you with your question!

Since the problem statement only gives us one point, we need to use point-slope form to find the equation of this line, instead of two-point form. Since we have the point (7,-2), we need to figure out what the slope of the line needs to be. If our line needs to be perpendicular to the line given in the problem statement, first we need to figure out the slope of THAT line. The equation of that line is x+3y=15, or y = -(1/3)x + 5. The slope of the line is -1/3. A perpendicular line must have a slope that is the negative reciprocal of -1/3, thus the slope must be 3.


Now we know that our line must go through the point (7,-2) and should have a slope 3. We can use point-slope form: y-y1 = m(x-x1), where y1 = -2, x1 = 7, and m = 3. We have y+2 = 4(x-7), or y + 2 = 4x - 28, or y = 4x - 30, which is the solution.

Please let me know if you need any clarification. I'm always happy to answer your questions.
Nov 12th, 2015

where did you get the 4?  you put the m=3 and then put y+2=4(x-7). how did you get the 4?


Nov 12th, 2015

where did you get the 4?  you put the m=3 and then put y+2=4(x-7). how did you get the 4?


Nov 12th, 2015
where did you get the 4? you put the m=3 and then put y+2=4(x-7). how did you get the 4?
Nov 12th, 2015

Did you know? You can earn $20 for every friend you invite to Studypool!
Click here to
Refer a Friend
...
Nov 12th, 2015
...
Nov 12th, 2015
Dec 4th, 2016
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer