Question

Me ajudem de novo

X2+8x+15=0

X2-6×+5=0

X2-×-6=0

X2-×-12=0

Answer 1

a) 
Δ= 8² -4.1.15
Δ= 64-60
Δ= 4

x= $\frac{-8 +- \sqrt{4} }{2.1}$

x¹=$\frac{8-2}{2}$= 2

x²=$\frac{8+2}{2}$= 5

b) 
Δ= -6² -4.1.5
Δ= 36-20
Δ=16

x= $\frac{6+- \sqrt{16} }{2.1}$

x¹=$\frac{6-4}{2}$=1

x²=$\frac{6+4}{2}$=5

c)
Δ=-1² -4.1.-6
Δ=1+24
Δ=25

x= $\frac{1 +- \sqrt{25} }{2.1}$

x¹=$\frac{1-5}{2}$= -2

x²=$\frac{1+5}{2}$= 3

d)
Δ=-1² -4.1.-12
Δ=1+48
Δ=49

x=$\frac{1+- \sqrt{49} }{2.1}$

x¹=$\frac{1-7}{2}$= -3

x²=$\frac{1+7}{2}$= 4