x+y=3 minusx y=3-x sub x(3-x)=-30 3x-x^2=-30 times -1 both sides x^2-3x=30 minus 30 both sides x^2-3x-30=0 use quadratic for ax^2+bx+c=0 x=[tex] \frac{-b+/- \sqrt{b^2-4ac} }{2a} [/tex]
1x^2-3x-30=0 a=1 b=-3 c=-30
x=[tex] \frac{-(-3)+/- \sqrt{(-3)^2-4(1)(-30)} }{2(1)} [/tex] x=[tex] \frac{3+/- \sqrt{9+120} }{2} [/tex] x=[tex] \frac{3+/- \sqrt{129} }{2} [/tex] the numbers are [tex] \frac{3+ \sqrt{129} }{2} [/tex] and [tex] \frac{3- \sqrt{129} }{2} [/tex]