Question

Factor completely. 20x^6+81x^3+81

Answer 1

Is there another way to do without ac method

Answer 2

not sure what you mean by the ac method

Answer 3

AC ----> any calculator :)

Answer 4

It's quadratic?

Answer 5

yea you could change it to a quadratic by letting y = x^3 then factor
20y^2 + 81y + 81

Answer 6

factor this then substitute back x^3 for y

Answer 7

I'm aware of the quadratic part where I treat it like a quadratic but my question is how can I find factors of 1620 without a calculator. It's such a large number

Answer 8

@cwrw238

Answer 9

And I wasn't given a calcular and I had very little time

Answer 10

start dividing 1620 by 20 or 21

Answer 11

when you divide 1620/20 you get 81 but 81 and 20 is 101 so you can have idea that you need to divide by some bigger number

Answer 12

then try 1620/30 you get 54
54 + 30 equal 84 so close to81
then i will jump to 36 1620/36 = 45
and 36 + 45 = 81 looks right

Answer 13

well this is how i will this problem if i get it in exam :) :(((

Answer 14

solve ***

Answer 15

Yeh. THIS would take some time if I hD only 25 mins for 20 questions

Answer 16

sound like SAT question :P

Answer 17

another way is to look at the factors of 20 and 81 and see how you can get 2 numbers to add up to 81