Question

Resolva as equações usando formula de Bháskara:

a) 2K² + K - 2 = 8

b) K² - 4 = 12

Answer 1

2K²+K-2-8
2K²+k-10
Δ=1²-4×2×(-10)
Δ=1+80
Δ=81    √Δ=√81      √Δ=9

k'= $\frac{-1+9}{4} = \frac{8}{4}$
k'=2

k''= $\frac{-1-9}{4} = \frac{-10}{4}$
k''= 2,5

b)k²-4=12
k²-4-12=0     k²-16=0
a=1   b=0  c= -16

Δ=0²-4×1×(-16)
Δ=64      √Δ=√64      √Δ=8

k'= $\frac{0+8}{2} = \frac{8}{2}$
k'=4

k''=$\frac{0-8}{2} = \frac{-8}{2}$
k''= -4