## anonymous one year ago x-2y=-8? (finding slope)

• This Question is Open
1. anonymous

need some help?

2. anonymous

alright the easiest way to find the slope is to convert it to slope intercept form

3. anonymous

sorry i gotta go,,, remember y=mx+b, m is the slope

4. anonymous

every time I "finish" my equation it becomes wrong somehow. so far I've done -2Y=-8-x and divide that which gets me Y=4-x

5. anonymous

they're saying it's wrong...

6. FireKat97

x - 2y = -8 so you want to get it in the form y = mx + b so you can simply read off the slope

7. FireKat97

so try rearranging the equation and post up what you get

8. anonymous

slope equals positive 1/2

9. whpalmer4

$x-2y=-8$ One way to get the slope (as other posters have suggested) is to rearrange the equation in slope-intercept form, or $y = mx + b$You can then "read off" the slope ($$m$$) and the y-intercept value ($$b$$). To do this, just solve your equation for $$y$$: $x-2y = -8$add $$2y$$ to both sides $x-2y+2y = -8+2y$$x=-8+2y$add $$8$$ to both sides $x+8 = -8+8+2y$$x+8 = 2y$divide both sides by $$2$$$\frac{x}{2} + \frac{8}{2} = \frac{2y}{2}$$\frac{1}{2} x + 4 = y$swap sides for conveniences $y = \frac{1}{2} x + 4$ comparing with our slope-intercept form $$y = mx + b$$ we see that $$m =\frac{1}{2}$$ and so our slope is $$\frac{1}{2}$$.

10. whpalmer4

Another approach is to just find two points on the line and use the formula for the slope of a line passing through two points: $m = \frac{y_2-y_1}{x_2-x_1}$where the line passes through points $$(x_1,y_1)$$ and $$(x_2,y_2)$$ To find out points, pick some values that will be easy to compute. $$x=0$$ is usually a good one, let's try it: $x=0,\ y = \frac{0}{2}x+4= 4$so the point $$(0,2)$$ is our first point, $$(x_1,y_1)$$ As we have that pesky $$\frac{1}{2}$$ in the formula, let's use a value of $$2$$ for $$x$$ for the other point to eliminate the fraction: $x = 2, \ y = \frac{1}{2}(2) + 4 = 5$ So $$(2,5)$$ is our other point, $$(x_2,y_2)$$ Let's plug those points into the formula for the slope: $m = \frac{y_2-y_1}{x_2-x_1} = \frac{5-4}{2-0} = \frac{1}{2}$ Look at that, we got the same answer. Good thing, too!

11. whpalmer4

sorry, I mistyped that equation for the first point in the previous post: $x=0,\ y = \frac{0}{2}x+4= 4$should be$x=0,\ y = \frac{1}{2}(0)+4= 4$