Question

why is x^2 - 16
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x^2 - 4x a perfect square ?

Answer 1

because you can separate it into two equations with the same and opposite number..? I don't know how to explain this ^_^'
(x-4)(x+4)

Answer 2

but why 4 ?

Answer 3

it multiplies to 16

Answer 4

ohhhhhhhh ok

Answer 5

Not really a good explanation but it's all I got :P

Answer 6

I don't think its a perfect square as it factorises to

\[\frac{(x + 4)(x -4)}{x(x - 4)}\]

Answer 7

just a thought

Answer 8

>.< I did not see that fraction there..

Answer 9

how do i do 3x^2 + 15

Answer 10

factor out a 3

Answer 11

a perfect square

\[(a + b)^2 = (a + b)(a + b) = a^2 + 2ab + b^2\]

I always thought they has 3 terms...

your question has the difference of 2 squares in the numerator and a quadratic binomial in the denominator

Answer 12

u cant its just 3 isnt it ?

Answer 13

ohh ok @campbell_st

Answer 14

3(x^2+5)

Answer 15

wait are you solving it?

Answer 16

howd u get that :/

Answer 17

u cant do anything with the 3 so it stays like that ..
x^2 , one will go with the 3 (3x) and the other in parenthesis 3x(x
but howd u get + 5 ? cuz of 3 * 5 ? 3x(x + 5)

Answer 18

Yup

Answer 19

k thanks