Question

a) x2 – 3x - 28 = 0

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Answer 1

a) x^2-3x-28=0

a=1

b=-3

c=-28

∆=b^2-4.a.c

∆=(-3)^2-4.1.(-28)

∆=9+112

∆=121

x'=-b+-√∆/2a

x'=-(-3)+11/2

x'=3+11/2

x'=14/2

x'=7

x"=-(-3)-11/2

x"=3-11/2

x"=-8/2

x"=-4

S={-4,7}

Answer 2

as raízes são -4 e 7

espero ter ajudando...