Question

gentee me ajude .... resolva as equações do 2°grau
a)×2-3×-4=0
b)×2+8×+16=0
c)3×2-2×-1=0
d)4×2-2×+1=0
e)5×2+4×-1=0
f)×2-7×+1=0​

Answer 1

Explicação passo-a-passo:

A)

x²-3x-4=0

∆=b²-4*a*c

∆=3²-4*1*(-4)

∆=9+16

∆=25

x= -b±√∆/2

x=-(-3)±√25/2

x= 3±5/2

x'= 3+5/2 =8/2=4

x''=3-5/2= -2/2= -1

B)

x²+8x+16=0

∆=b²-4*a*c

∆=8²-4*1*16

∆=64-64

∆=0

x= -b±√∆/2

x=-8±√0/2

x= 8±0/2

x'= 8+0/2=8/2=4