Question

Resolva as seguintes equações:
a) 9x² - 6x - 24 = 0
b) 6x² - 13x + 6 = 0
c) x² + 2x - 3 = 0
d) x² + 7x - 8 = 0

Answer 1

a) 9x^2-6x-24=0
delta=b^2-4ac
delta=(-6)^2-4.9.(-24)
delta=36+864
delta=900
x=-b-/+ raiz de delta/2a
x=-(-6)-30/2.9
x=6-30/18
x=-24/18 (:6)
x=-4/3
x=-(-6)+30/2.9
x=6+30/18
x=36/18
x=2
b) 6x^2-13x+6=0
delta=b^2-4ac
delta=(-13)^2-4.6.6
delta=169-144
delta=25
x=-b-/+ raiz de delta/2a
x=-(-13)-5/2.6
x=13-5/12
x=8/12 (:4)
x=2/3
x=-(-13)+5/2.6
x=13+5/12
x=18/12 (:6)
x=3/2
c) x^2+2x-3=0
delta=b^2-4ac
delta=2^2-4.1.(-3)
delta=4+12
delta=16
x=-b-/+ raiz de delta/2a
x=-2-4/2.1
x=-6/2
x=-3
x=-2+4/2.1
x=2/2
x=1
d) x^2+7x-8=0
delta=b^2-4ac
delta=7^2-4.1.(-8)
delta=49+32
delta=81
x=-b-/+ raiz de delta/2a
x=-7-9/2.1
x=-16/2
x=-8
x=-7+9/2.1
x=2/2
x=1