You are here:

Basic Math/straight line equations

Advertisement

Expert: - 6/1/2005


Question
dear mr. mantell,
i have been searching many sites to help me with the y-intercept formula and i went to purple math and they gave me this example, it was very helpful but i was wondering if you could go through each step to tell me what is going on.

y=mx+b
1. 2=(-2/3)(1)+b
2. 2=-2/3+b
3. 2+2/3=b
4. 6/3+2/3=b
5. b=8/3


Answer
Hello Tiffani,

This example shows a line with a slope of -2/3, which
contains the point (1,2).
1. substituted x=1 and y=2
2. simplified (-2/3)(1)
3. added 2/3 to both sides
4. common denominator
5. b=8/3, which is the y-intercept.

OK?

Abe

Basic Math

All Answers

Answers by Expert:

Ask Experts

Volunteer

Abe Mantell

Expertise

Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!

Experience

Over 15 years teaching at the college level.

Organizations belong to
NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.

Education/Credentials
B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook

©2012 About.com, a part of The New York Times Company. All rights reserved.