Question

escreva as equações na forma geral e resolva

Answer 1

a) x^2+3=4x
x^2-4x+3=0
delta=b^2-4ac
delta=(-4)^2-4.1.3
delta=16-12
delta=4
x=-b-/+ raiz de delta/2a
x=-(-4)-2/2.1
x=4-2/2
x=2/2
x=1
x=-(-4)+4/2.1
x=4+4/2
x=8/2
x=4
b) -20=-x-x^2
x^2+x-20=0
delta=b^2-4ac
delta=1^2-4.1.(-20)
delta=1+80
delta=81
x=-b-/+ raiz de delta/2a
x=-1-9/2.1
x=-10/2
x=-5
x=-1+9/2.1
x=8/2
x=4
c) 13-2x-15x^2=0
-15x^2-2x+13=0
delta=b^2-4ac
delta=(-2)^2-4.(-15).13
delta=4+780
delta=784
x=-b-/+ raiz de delta/2a
x=-(-2)-28/2.(-15)
x=2-28/-30
x=-26/-30 (:2)
x=-13/-15
x=-(-2)+28/2.(-15)
x=2+28/-30
x=30/-30
x=0