Question

7. Resolva as equações.
a)
${x}^{2} - 25 = 0$
b)
$2 {x}^{2} - 98 = 0$
c)
$24 = 6 {x}^{2}$
d)
$64 {x}^{2} - 1 = 0$
e)
$7 {x}^{2} - 14 = 0$
f)
$- {x}^{2} + 49 = 0$
g)
$- 25 + 100 {x }^{2} = 0$
h)
${x}^{2} - \frac{81}{4} = 0$

Answer 1

a) x^2 = 25
x = 5

b) 2x^2 = 98
x^2 = 98/2
x^2 = 49
x = 7

c) 6x^2 = 24
x^2 = 24/6
x^2 = 4
x = 2

d) 64x^2 = 1
x ^2 = 1 /64
x = 1/8

e) 7x^2 = 14
x^2 = 14/7
x^2 = 2
Aqui fica: x = raiz de 2

f) -x^2 = - 49 . (-1)
x^2 = 49
x = 7

g) - 25 + 100x^2 = 0
100x^2 = 25
x^2 = 25/100
x = 5/10

h)x^2 - 81/4 = 0
x^2 = 81/4
x = 9/2