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High-Tier Algebra Question

I'm currently stuck on a maths technicality.

The question begins as (3/x+2)+(1/x-2)=(7/x²-4) (meant to be fractions by the way)

I've reached the point of: 4x³-11x²+12=0 but I don't know where to go from here.

Have I done it incorrectly or is there another step that I'm missing?

Reply 1

the bear

if you add the LHS fractions carefully you will find that the underneath is x² -4...

Reply 2

jcrosswarren

Original post by the bear

if you add the LHS fractions carefully you will find that the underneath is x² -4...

What do you mean?

Reply 3

the bear

3/( x + 2 ) + 1/( x - 2 )

is the same as

{ 3( x - 2 ) + 1( x + 2 ) }/ ( x + 2 )( x - 2 )

Reply 4

jcrosswarren

Ohhhhhh I get you now. Yeah, I did that originally. I came to (4x-4)/x²-4=7/(x²-4) and then thought I had to do (x²-4)(4x-4)=7(x²-4)

I then got to 4x³-4x²-16x+16=7x²-28

Is that the wrong thing to do?

(edited 8 years ago)