Question

2x=15-x^2 Me ajudem por favor!!!!!!!!

Answer 1

vamos lá...

2x=15-x²
ordenando

x²+2x-15=0

a=1
b=2
c=-15

Δ=b²-4ac
Δ=2²-4(1)(-15)
Δ=4+60
Δ=64

$x= \frac{-b\pm \sqrt{\triangle} }{2a} = \frac{-2\pm \sqrt{64} }{2} = \frac{-2\pm \sqrt{64} }{2} = \frac{-2\pm8}{2} \\ \\ x'= \frac{-2+8}{2} = \frac{6}{2} =3 \\ \\ x"= \frac{-2-8}2} =- \frac{10}{2} =-5 \\ \\ S=\{-5,3\}$