Question

y²+y-56=0

Fórmula de Bháskara

Answer 1

y=x
∆=b²-4•a•c
∆=1²-4•1•(-56)
∆=1+224
∆=225
x=-b±√∆/2•a
x=-1±√225/2•1
x=-1±15/2
x'=-1-15/2= -16/2= -8
x"=-1+15/2= 14/2= 7

Answer 2

fórmula geral: ay² + by + c = 0     =>>>  no seu caso: a=1 , b= 1 e c= -56

Δ= b²-4ac = 1² - 4x1x(-56) = 1+224=225 =>√Δ=√225 = 15

y= (−b±√Δ)/2a =( -1±15)/2 

y1 = (-1-15)/2 = -16/2 = -8
y2 = (-1+15)/2 = 14/2 = 7
 
resposta: -8 e 7