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Mick Mick
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Posts: 31
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11 years ago
I know slope intercept form is y=mx+b, but when I have an equation such as 3x+2y=10 or x+2y=2 I can't change it into slope intercept form to save my life and to solve the rest of the problem you have to change it into that format.

And can you please tell me how x+3y=7 becomes y=-1/3x+7/3? I don't understand how you get a fraction for that answer. Thanks.
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wrote...
11 years ago
just rearrange and make y as subject

x + 3y = 7

subtract x from both sides

3y = -x + 7

divide by 3

y = -(1/3)x + 7/3
wrote...
11 years ago
Very simple
x + 3y = 7
subtract the x to the other side
3y = -x + 7
divide by 3
y = (-x +7)/3 or you can put it your way y = -x/3 + 7/3

3x + 2y = 10
subtract 3x to other side
2y = -3x + 10
divide by 2
y = -3x/2 + 5      (10/2) = 5

x + 2y = 2
subtract x
2y = x+2
divde by 2
y = x/2 + 1      (2/2) = 1
wrote...
11 years ago
3x+2y=10 would be y= -3/2x +5

x+2y=2 the slope intercept form is y= -1/2x +1

The way you solve  x+3y=7 is first bring over the x by subtracting.

You now have 3y= -x+7, Then divide both sides by 3 and you get the answer y=-1/3x+7/3
wrote...
11 years ago
you must solve for y, or get it by itself... this means to get y= (something).

I will show the work and then explain it...

x+3y=7                    There are 2 terms on the left side of this equation
-x       -x                   you need to put the x on the other side so now    
                                 it is just the y on the left side.
3y= - x + 7           here the x is negative because you subtracted it
/3        /3               now you must divide by 3 to get y by itself
y= -1/3x +7/3         make sure each term on the left is divided by 3.


I hope this helps.
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