Question

As raízes 2/3 e 3/5 pertencem a equação: A)6x2-19+15=0 B)15x²-6x+19=0 C)15x²-19x+6=0 D)18x²-6x+15=0 e)18x²-15x+6=0

Answer 1

Letra C ...

a = 15

b = - 19

c = 6

Achando o delta.

Δ=b²-4.a.c

Δ= (-19)² -4.15.6

Δ=361-360

Δ=1

Achando Bhaskara

x=(-b+-√Δ)/2.a

x'= - (-19 +√1)/2.15

x'=+19+1/30

x'=20/30 ÷ 10

x'=2/3

x"= - (-19-√1)/2.15

x"= +19 - 1/30

x"= 18/30 ÷ 6

x"= 3/5

S={x'+2/3 e x"=3/5}.