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Help Me With This Maths Problem

Solve this to 2dp:

2x+3/x-4 - 2x-8/2x+1 = 1

Really don't understand this problem, what do I have to do? :L
(edited 7 years ago)
Original post by romansholiday
Solve this to 2dp:

(2x+3)/(x-4) - (2x-8)/(2x+1)

Really don't understand this problem, what do I have to do? :L


you would be basically cross multiplying then due to the 2dp you would have to use the quadratic formula im assuming
I'm assuming you want the value of x
Open up the brackets and use the quadratic equation to work it out
Original post by chrlhyms
you would be basically cross multiplying then due to the 2dp you would have to use the quadratic formula im assuming


I forgot to add the = 1 on the end, does this make any difference?
Original post by romansholiday
Solve this to 2dp:

2x+3/x-4 - 2x-8/2x+1 = 1

Really don't understand this problem, what do I have to do? :L


cross multiply to get 2x+3(2x+1)- (2x-8)(x-4)/(X-4)(2x+1) = 1 , then times the 1 by the denominator to get 2x+3(2x+1) -(2x-8)(x-4)= (x-4)(2x+1)
Original post by romansholiday
I forgot to add the = 1 on the end, does this make any difference?


yeah because you would have to times the denominators by 1 and then rearrange
1. Multiply by (x-4)(2x+1) so it's"
(2x+3)(2x+1) - (2x-8)(x-4)

2. Expand the brackets
4x^2+8x+3 - 2x^2-16x+32
= 2x^2-8x+35

3. Solve using the quadratic formula
a=2, b=-8, c=35
Original post by romansholiday
Solve this to 2dp:

2x+3/x-4 - 2x-8/2x+1 = 1

Really don't understand this problem, what do I have to do? :L


Step by step:
First you expand:
2x+3(2x+1)- (2x-8)(x-4)/(X-4)(2x+1) = 1
and then times the 1 by the denominator which equals to:
2x+3(2x+1) -(2x-8)(x-4)= (x-4)(2x+1)
Reply 8
Original post by GlassyMarbles
1. Multiply by (x-4)(2x+1) so it's"
(2x+3)(2x+1) - (2x-8)(x-4)

2. Expand the brackets
4x^2+8x+3 - 2x^2-16x+32
= 2x^2-8x+35

3. Solve using the quadratic formula
a=2, b=-8, c=35

Wouldn't it be 2x^2-8x-29? Instead of 2x^2-8x+35
Original post by Kiniun
Wouldn't it be 2x^2-8x-29? Instead of 2x^2-8x+35


No idea, did it in a rush. You're probably right though, I tend to make stupid mistakes during multiple-step maths questions.
Reply 10
Original post by GlassyMarbles
No idea, did it in a rush. You're probably right though, I tend to make stupid mistakes during multiple-step maths questions.



If you think that's a stupid step, you should see my 5x2=7 mistakes in exams loool
It got x = 25/31. Did anyone else get that?
Original post by Kiniun
If you think that's a stupid step, you should see my 5x2=7 mistakes in exams loool


Hahaha I get you, I wrote 26-16=8 in an exam once
Original post by phat-chewbacca
It got x = 25/31. Did anyone else get that?


I got the same!!! :smile: Turns out quadratic formula was unnecessary cuz the x^2s cancel out

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