Respuesta :

44)
5x ^ 2 - 10 = x ^ 2 + 90
4x ^ 2 = 100
x ^ 2 = 25
x = 5, -5
45)
x ^ 2 - 6x + 9 = 0
(x - 3) ^ 2 = 0   <---this kind of just comes from experience... not sure how to explain it...
x - 3 = 0
x = 3