Explicación paso a paso:
a)
x^2 = 121
[tex]x = \sqrt{121} [/tex]
x = 11
x = - 11
b)
20 - 5x^2 = - 105
-5x^2 = - 125
x^2 = 25
x = 5
x = - 5
c)
6x = - 3x^2 +24
3x^2 +6x - 24 = 0
x ^2 +2x - 8 = 0
(x+4) (x-2) = 0
x = - 4
x = 2
d)
x ^2 = 20 - x
x^2 +x - 20 = 0
(x +5) (x -4) = 0
x = 4
e)
4x(x-4) = - 12x +3
4x^2 - 16x = - 12x + 3
4x^2 - 4x - 3 = 0
x^2 - x - 3/4 = 0
(x - 3/2) (x + 1/2) = 0
x = 3/2
x = - 1/2
