Select all of the following equation(s) that are quadratic in form.
x4 – 6x2 – 27 = 0
3x4 = 2x
2(x + 5)4 + 2x2 + 5 = 0
6(2x + 4)2 = (2x + 4) + 2
6x4 = -x2 + 5
8x4 + 2x2 – 4x = 0

How far is x from 5 on a number line?

An episode of a television show is 60 minutes long when it originally airs with commercials. on a dvd without commercials, the episode is only 417 minutes long. how many1-minute commercials did the episode include when it originally aired? write and solve an equation to justify your answer.

Si la base de un triángulo isósceles mide 70 m y el ángulo opuesto a ésta mide 58°; entonces ¿cuánto mide la altura de dicho triángulo? a) 21.87 m. b) 40.01 m. c) 43.74 m. d) 63.14 m.