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#1 2005-10-20 11:49:20

Jack A
Guest

Help with Evil Simultaneous Equation

Hello,

After completing a page of Simultaneous Equations i am stuck with this. suddenly i have x and y's everywhere, and keep rearaging it wrong. please show me what to do. even if its just a little clue.

Solve for x and y:


4 + (4y ÷ x)  = -4x^-1   and   x^2 + 7xy = 19x


Thanks, J

#2 2005-10-20 12:26:12

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Help with Evil Simultaneous Equation

4 + 4y / x = 1 / -4x  -> multiply by x
4x + 4y = -1/4
4y = -4x - 1/4
y = -x - 1/16

x^2 + 7xy = 19x   -> divide by x
x + 7y = 19
x = 19 - 7y

I would use the substitution method to solve the system:
y = -(19 - 7y) - 1/16
y = 7y - 19 - 1/16
-6y = -305 / 16
y = 305 / 96

Last edited by ryos (2005-10-20 12:27:12)


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