Question

$x^{2} -3x-28=0$ equação do 2°Grau

Answer 1

x^2 - 3x - 28 = 0
delta = b^2 - 4.a.c
delta = (-3)^2 - 4.1.(-28)
delta = 9 + 112
delta = 121
x = -b +_ raiz delta / 2.a
x = -(-3) +_ 11 / 2
x = 3 +_ 11 / 2
x* = 3 - 11 / 2
x* = - 8/2
x* = - 4

x** = 3 + 11 / 2
x** = 14 / 2
x** = 7

S = { -4, 7 }

Answer 2

$x^{2} -3x-28=0= \Delta= b^{2} -4.a.c= \Delta= -3^{2} -4.1.(-28)= \Delta=9+112=121 x^{1}=-3-+ \sqrt{121} /2=-3+11/2=8/2=4 x^{2} =-3-+ \sqrt{121} /2=-3-11/2=-14/2=-7$

S={4,-7}