[Blueray2]

2u^2 - 7u - 6 = 0

How do I do a quadratic equation like this?
Can you tell me a step by step method, thanks

Keeping in mind I can't use a calculator

[notnek]

(Original post by Blueray2)
2u^2 - 7u - 6 = 0

How do I do a quadratic equation like this?
Can you tell me a step by step method, thanks

Keeping in mind I can't use a calculator

The left-hand-side can't be factorised so the best way is to use the quadratic formula and leave your answer in terms of surds (square roots).

Have you done that before? Post any ideas/working if you're still stuck.

[TheMagicMan]

(Original post by Blueray2)
2u^2 - 7u - 6 = 0

How do I do a quadratic equation like this?
Can you tell me a step by step method, thanks

Keeping in mind I can't use a calculator

Well it doesn't factories (I think), so you should probably just use the quadratic formula (google it if you don't know)


This was posted from The Student Room's iPhone/iPad App

[boromir9111]

Quadratic formula that shizzle!

[TheHansa]

It won't factorise so we have to use the quadratic formula, it's often easier to use it anyway but the question sometimes specifies the method it wants you to use

The general formula for a quadratic function is ax^2+bx+c=0

and the quadratic formula is



Except in this question x is replaced by u, it makes no difference

so

a=2
b=-7
c=-6

So now it's simply a matter of substitution

once you have the answers write it in bracket form and give the roots

[TenOfThem]

(Original post by TheHansa)

once you have the answers write it in bracket form and give the roots

The quadratic formula gives the roots ... why would the OP need to put anything into brackets?

[TheHansa]

(Original post by TenOfThem)
The quadratic formula gives the roots ... why would the OP need to put anything into brackets?

He didn't say if he wants the roots or to factorise.