# My teacher says this linear equation is wrong, I think she is wrong.

• Aug 11th 2009, 12:56 PM
bobbyboy1111
My teacher says this linear equation is wrong, I think she is wrong.
4. (-7) = (-2)(-2) + b

(-7) = (4) + b

-11 = b

y = -2x -11

I don't see anything wrong with this(Smirk) Do you?
• Aug 11th 2009, 12:58 PM
Matt Westwood
Looks okay to me. What does she think it ought to be? Maybe it's the bit that leads up to this what's wrong.
• Aug 11th 2009, 04:58 PM
HallsofIvy
Quote:

Originally Posted by bobbyboy1111
4. (-7) = (-2)(-2) + b

(-7) = (4) + b

-11 = b

y = -2x -11

I don't see anything wrong with this(Smirk) Do you?

What was the question? The only thing "wrong" with that is that it doesn' maqke any sense at all! Why should "b" have anything at all to do with x and y? What are you trying to do?

Frankly, it looks to me like you have a very good teacher who is concerned about your tendency to do algebraic operations without thinking about what you are doing.
• Aug 11th 2009, 11:28 PM
bobbyboy1111
Quote:

Originally Posted by HallsofIvy
What was the question? The only thing "wrong" with that is that it doesn' maqke any sense at all! Why should "b" have anything at all to do with x and y? What are you trying to do?

Frankly, it looks to me like you have a very good teacher who is concerned about your tendency to do algebraic operations without thinking about what you are doing.

It does because it is a linear equation and it turns out I was right, relating what I said.

NO.
• Aug 12th 2009, 01:59 AM
Stroodle
Quote:

Originally Posted by bobbyboy1111
It does because it is a linear equation and it turns out I was right, relating what I said.

NO.

No it doesn't...
• Aug 12th 2009, 02:05 AM
pacman
The problem may be have this given values, slope = m = -2; then the line passes through points (-2,-7). find the equation of the line.
y = mx + b, where m = -2 and points (-2,-7), substituting
(-7) = (-2)(-2) + b
(-7) = (4) + b
-11 = b
y = -2x -11. This is the slope-intercept form and seems alright.

What if you have interchanged the point (-7,-2) to (-2,-7)?

Or you have the wrong form of the equation of the line . . . .(Surprised)
• Aug 12th 2009, 02:15 AM
mr fantastic
This thread has required constant moderation from the go get. It has become too troublesome to keep opened.