For the system shown below, what are the coordinates of the solution that lies in quadrant I? x^2-y^2=25
x+y=25

Question

For the system shown below, what are the coordinates of the solution that lies in quadrant I? x^2-y^2=25 
x+y=25

anonymous · Answer

from second one, isolate x, what do you have?

samsan9 · Answer

y=-x+25

anonymous · Answer

hihi, I suggest isolate x, you isolate y, but it's ok, now square both sides, show me what you have

samsan9 · Answer

oh my bad its x=-y+2 and squaring both sides gives me x^2=Y^2+20

anonymous · Answer

no!!! the left hand side is x^2 but the right hand side is (-y+25)^2 or (25-y)^2 , open this perfect square, it is not y^2 +20, redo, please

samsan9 · Answer

x^2=y^2-50y+100

anonymous · Answer

yup, now, take that x^2 replace to the first equation, what do you have?

anonymous · Answer

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