Algebra problems ! Help !?
This is parallel and perpendicular lines.
Write the slope-intercept form of an equation of the line that passes through the given poins and is parallel to the grapgh of each equation.
1) (-5,-1) 2y= 2 x - 4
2) (3,-1) 3y= x + 9
3) (-1,1) y= x - 4
4) (-4,2) y= x + 3
Comments
use a text book
I'll show you an example.
1) 2y=2x-4 You need to simplify this by dividing both sides by 2
y=x-2 Since you're looking for a parallel line, you know that the number must have the same slope, which for this problem is 1
Since you already know the slope for the equation, you just need to find the y-intercept, which is represented by the variable b.
You would start with the equation y=x+b and substitute -5 in for x and the -1 for y and you should have something that looks like this: -1=-5+b
From there, you could just use simple algebra to bring the -5 over to the left side and divide by -1. You would get 4 for your y-intercept so your equation would be y=x+4
1) first put the equation in slope intercept form: 2y=2x-4 -> y=x-2, Now you know the slope since anything with the same slope will be parallel and visa versa. Now you have y=x+m, now plug in (-5,-1) for x and y so that you get -1=-5+m and solve for m. m=4. Now plug that back into the problem -> y=x+4
Do the same for the rest:
2) 3y=x+9 -> y=(1/3)x+3, so y=(1/3)x+m -> -1=(1/3)*3+m, so m=-2 so the answer is y=(1/3)x-2
you can do the same for the rest.
slope-intercept form
Sing it like 99 bottlesof beer
y=mx+b is a line y=mx+b is a line
m is the slope and b is where it passes through the y-intercept
Pay attention in class, kid. You have to learn yourself.
Google about it. Then try it yourself. Try asking your parents.