[alex7892]

4x-480x^-2=0
howq do i solve? step by step? Thanks all!

[Coulson72]

try multiplying by x^2

[alex7892]

(Original post by Coulson72)
try multiplying by x^2

Okay sweet I got : 4x^3-480=0
4x^3=480
x^3=120
x= 3 root 120 = 4.9...
Thanks alot btw, but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!

[Coulson72]

well if you get summit similar try multiplying by enough to turn the biggest negative into a 0, so like if you have 2x^2+5x^-3=0 then you'd try multiplying by x^3 to turn the -3 into a 0

[Intriguing Alias]

(Original post by alex7892)
Okay sweet I got : 4x^3-480=0
4x^3=480
x^3=120
x= 3 root 120 = 4.9...
Thanks alot btw, but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!

Well it's better to get rid of the fractions or negative power (by this I mean or ). So multiply by whatever you need to get rid of the negative power.

[alex7892]

Thanks all great help. Love feeling confident about maths and getting it haha!!

[steve2005]

(Original post by alex7892)
Okay sweet I got : but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!

Suppose you have been given permission to drive your friends car. You are given a large bunch of keys. How do you KNOW which key to use?

What would you do? I guess most people would try one key, then another and so on.

It's the same with mathematics. JUST try and see what happens.