# I dont get this questionWatch

#1
9. Show that 1/(〖6x〗^2+7x-5)÷1/(〖4x〗^2-1) simplifies to (ax+b)/(cx+d), where a, b¸ c and d are integers.
0
11 months ago
#2
when you divide a fraction by another fraction, flip the second fraction and then multiply the 2 fractions together. then factorise and simplify.
0
11 months ago
#3
(Original post by confusedchildren)
9. Show that 1/(〖6x〗^2+7x-5)÷1/(〖4x〗^2-1) simplifies to (ax+b)/(cx+d), where a, b¸ c and d are integers.
Rewrite the expression as a single fraction first.
0
#4
(Original post by amaraub)
when you divide a fraction by another fraction, flip the second fraction and then multiply the 2 fractions together. then factorise and simplify.
i did the first part and got 4x^2 - 1 / 6x^2 + 7x -5 but idl how to factorise that
0
#5
(Original post by RDKGames)
Rewrite the expression as a single fraction first.
i got 4x^2 - 1 / 6x^2 + 7x -5
0
11 months ago
#6
(Original post by confusedchildren)
i got 4x^2 - 1 / 6x^2 + 7x -5
Great, now factorise the numerator and denominator.
0
11 months ago
#7
(Original post by confusedchildren)
i did the first part and got 4x^2 - 1 / 6x^2 + 7x -5 but idl how to factorise that
i'd suggest you brush up on factorising quadratics then, there are plenty of videos on youtube etc
0
#8
(Original post by RDKGames)
Great, now factorise the numerator and denominator.
im stuck i dont know how to do it
0
11 months ago
#9
(Original post by confusedchildren)
im stuck i dont know how to do it
The numerator is a difference of two squares (something I recommend knowing by heart) whereby hence .

To factorise the denominator , do you have any methods you went over that you can use?

If not, then a nice way is to think of two numbers which multiply to make and add to make . What are they?? Then split the middle 7 as a sum of these two numbers with coefficient of . Then factorise.
0
#10
(Original post by RDKGames)
The numerator is a difference of two squares (something I recommend knowing by heart) whereby hence .

To factorise the denominator , do you have any methods you went over that you can use?

If not, then a nice way is to think of two numbers which multiply to make and add to make . What are they?? Then split the middle 7 as a sum of these two numbers with coefficient of . Then factorise.
so i got -3 and 10 as the two numbers so it was 6x^2 -3x +10x -5 and i factorised it to get (2x-1)(3x+5) so i canceled (2x-1) from the numerator and denominator to get (2x+1)/ (3x+5) what do i do next?
0
11 months ago
#11
(Original post by confusedchildren)
what do i do next?
Celebrate.
1
#12
(Original post by RDKGames)
Celebrate.
Cant celebrate if ive still got 3 more questions left ugh XD but thanks again
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• University of Stirling
Thu, 26 Sep '19
• Heriot-Watt University
Fri, 27 Sep '19
• Royal Holloway, University of London
Sat, 28 Sep '19

### Poll

Join the discussion

#### Are you attending a Global Climate Strike?

Yes, I'm striking (26)
6.58%
No, but I wanted to/I support the cause (231)
58.48%
No (138)
34.94%