Question

me ajudem!!!
a)7x2-21=0
b)x2-49=0
c)(x+5)2=25
d)4x2-36=0

Answer 1

a)
7x - 21 = 0 => x = 21/7 => x = 3
b)
x^2 - 49  = 0 => x^2 = 49 => x = ±raiz(49) => x = ±7
c)
(x + 5).2 = 25 => 2x + 10 = 25 => 2x = 15 => x = 15/2 => x = 7,5
d) 
4x^2 - 36 = 0 => 4x^2 = 36 => x^2 = 36/4 => x = ±raiz(9) => x = ±3