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# Algebra? watch

1. Given that for all values of x
(4x + a)(x – 2) ≡ (2x + 1)2 + b
find the value of a and the value of b.

The 2 at the end of "(2x + 1)2" is meant to be squared
2. im having a go rn
3. Expand and compare coeffiecients.
4. are you multiplying the 2+b withthe (2x+1)
5. (Original post by shamithink)
are you multiplying the 2+b withthe (2x+1)
No, the 2 is meant to be a squared and its just +b
6. im stuck at a dead end
7. (Original post by shamithink)
im stuck at a dead end
expand and simplify
8. i've got
a=13-b all over -2
9. (Original post by shamithink)
i've got
a=13-b all over -2
i meant 13+b all over -2
10. now iv got a-b= -6.5
11. (Original post by shamithink)
im stuck at a dead end
If you expand and simplifiy both sides you get:
4x^2-8x+ax-2a=4x^2+4x+1+b

So comparing, we get:
a-8=4
and b+1=-2a
12. (Original post by shamithink)
now iv got a-b= -6.5
If you expand and simplifiy both sides you get:
4x^2-8x+ax-2a=4x^2+4x+1+b

So comparing, we get:
8-a=4
and b+1=-2a
You may want to check your workings on this
14. Once expanded and simplified we have the following:

-8x ax - 2a = 4x 1 b

Now solve for x and sub in to the right side of the equation to solve for b. I don’t know why it won’t let me put in my plus and minus signs but you should know where they go :/
15. you can do a square sign like this:

(2x + 1){sup}2{/sup}

but replace the { } brackets with [ ]

(2x + 1)2
16. (Original post by Y11_Maths)
I knew it was wrong, i shared my solution so i could learn where i went wrong and check over my workings out
17. (Original post by Y11_Maths)
You may want to check your workings on this
Pretty sure its right. Why, whats wrong with it?
Pretty sure its right. Why, whats wrong with it?

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