Question

Resolva as equações abaixo (Calculo):

a)x^2+3=4
b)-20=-x-x^2
c)13-2x-15x^2=0
d)4x^2+7x+3=2x^2+2x
e)x(x-2)=2(x+6)
f)x(2x-1)+6=4(x+1)
g)(x-1)(x-2)=6
h)(2x-3)(x-8)=34

Answer 1

a)x²=4-3
x²=1
x=+-√1
x=+-1

b)x²+x-20=0
∆=1²-4•1•(-20)
∆=1+80
∆=81
-1+-√81/2•1
-1+-9/2
x1=-5
x2=4

c)-15x²-2x+13=0
∆=(-2)²-4•(-15)•13
∆=4+780
∆=784
-(-2)+-√784/2•(-15)
4+-28/30
x1=32/30=16/15
x2=-24/30= -4/5