Posted by **Tyler** on Tuesday, February 26, 2008 at 9:10pm.

How to solve the two formulas for x+y=21 3x+4y=21

- Math -
**Vanessa**, Tuesday, February 26, 2008 at 9:17pm
you can use a substraction-or-addition method or substitude method.

So...

x+y=21 you multiply both side by 3 3x+3y=63

3x+4y=21

---------

then you eliminate one variable

you use the subtraction method

-y=42

y=-42

then you solve for x by substituting the y

x+(-42)=21

x=63

- Math -
**Reiny**, Wednesday, February 27, 2008 at 12:01pm
48.25 =4825/100 = 193/4 = 48 1/4

or just realize that .25 = 1/4

so 48.25 = 48 1/4

Please don't post a question as part of a previous thread, start a new topic

That way you will have a much better chance at a tutor looking at it.

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