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# simultaneous equations watch

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1. hi guys, can someone explain to me how im supposed to do these simultaneous equations, im totally useless at them,
appreciate all the help

1 - xy = 8
xy + 5x + 5y = 38

find values for x and y

2- x + 2y = 62
xy - 2x = 240
2. Do you have a restriction on the values of x and y? Because, for instance, the first set has infinitely many solutions.
3. no restrictions dvs,

i can think of the answwers easily, but i need to write down a method, which im not sure how to do
4. (Original post by c-note)
1 - xy = 8 (1)
xy + 5x + 5y = 38 (2)
From (1),
xy = -7
x = -7/y
From (2), -7 + 5(-7/y) + 5y = 38.
-45 - 35/y + 5y = 0
-45y - 35 + 5y^2 = 0, and solve.

Similar method on the second question.

(Original post by dvs)
Do you have a restriction on the values of x and y? Because, for instance, the first set has infinitely many solutions.
Not true, I think you got up to -7 + 5x + 5y = 38 and neglected to see that x and y were still linked in the first equation.

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