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#1 2011-06-19 07:10:50

lena
Guest

swich equation to y=mx+b

hey can any body help my switch these equation to an slope intercept form

x + 2y = -4

x + y = 3

x + 3y = -6

#2 2011-06-19 11:35:40

MathPro101
Member
Registered: 2011-06-08
Posts: 18

Re: swich equation to y=mx+b

Slope intercept form is the form y=mx+b.

This means that in each equation, we must solve for y in terms of x and a constant, b.

To solve for y, we need to have it alone on one side. In order to do that, we must move x to the other side. In all three equations, x is being added to y on the left side, so in order to move x over, we must subtract x from the left side. But whatever we do to the left side we must do to the right side. So after one step, you should have

x + 2y - x= -4 - x

x + y - x= 3 -x

x + 3y - x= -6 - x


which is the same as

2y= -4 - x

y= 3 -x

3y= -6 - x

Now, the second equation is in slope-intercept form, but the first and third are not. We must apply the same algebraic strategy that we did in the first step to get y alone. For example, in the first equation, y is being multiplied by 2. So in order to get rid of the two, we must divide the y by 2. But we must also divide the WHOLE right side by two, not just the -4. Once you do that for the first and third equation, you should end up with


y= -2 - x/2
y= 3 - x
y= -2 -x/3


Does that help?

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