Ceia Exum
May 13, 2009, 01:27 PM
please show me a step by step procedure.
find the slope of the line y=2/5x+6
Solve: 5(x+4)<-4+5x
find the slope passing through the points A(-5,-5) and B(6,1)
Solve: x+2-2(x+8)>0
Perito
May 13, 2009, 02:15 PM
1. find the slope of the line y=2/5x+6
2. Solve: 5(x+4)<-4+5x
3. find the slope passing through the points A(-5,-5) and B(6,1)
4. Solve: x+2-2(x+8)>0[/math]
1. The general form of a line is "y=mx+b". Where m and b are constants, not variables.
When you see an equation like this, the value of "m" is always the slope. The value of "b" is the "y-intercept" (or some people just say the "intercept".
Therefore, the answer to equation 1 is simply "2/5".
2.
5(x+4)<-4+5x -- Are you sure this is correct?
5x+20<4+5x
5x+20-20-5x < 4+5x-20-5x
0 < -16 -- which is impossible. Therefore, there is no solution.
3.
The slope of a line is given by
Slope = \frac {\Delta\,y}{\Delta\,x}
where "Δ" means the "change in"
You have two points, (-5,-5), and (6,1)
\Delta\,y = 6-(-5)=11
\Delta\,x = 1-(-5)=6
slope=\frac {\Delta\,y}{\Delta\,x}=\frac {11}{6}=1\, \frac 56
4.
x+2-2(x+8)>0
x+2-2x-16>0
-14-x>0
x<-14
You can add and subtract from both wides without changing > to < or < to >. However, if you multiply or divide, you have to be sure that you aren't using a negative number. Sometimes that's hard to do. If you do use a negative number, you change the sense. Here's an example
1 < 7
multiply both sides by -1 (or any negative number), the sense changes:
-1 \, \times \, 1 \, >\, -1 \, \times \, 7
-1 > -7