# Can anyone help with these two questions

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#1

2. find x as a fraction of 2x^½=9/8
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1 week ago
#2
(Original post by EDX_brutality)
2. find x as a fraction of 2x^½=9/8
But you're not after a value of x here.

You are after the values of a,b.

You need to construct two equations in a,b and solve them simultaneously.

E.g. from the first relation, we have therefore we must have .

Likewise with the second equality for another equation, hence solve for a,b.
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1 week ago
#3
(Original post by RDKGames)
But you're not after a value of x here.
I think 2. is a separate (and not terribly well laid out) question.
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#4
(Original post by DFranklin)
I think 2. is a separate (and not terribly well laid out) question.
Yh, they are separate questions lol
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1 week ago
#5
1) Laws of Indices play a large part in this question.

Start by expanding brackets, remembering that (xm ) n = xmn
This should provide you with a value of a in terms of b, since x2a = x8b , thus 2a = 8b , a = 4b
Sub this into the second equation and solve (similar to a simultaneous equation)

Key points to help: sqrt(x) = x1/2
x3 divided by xb
= x3-b
2) Similar skills, remember sqrt(x) = x1/2 From that you should be able to square both sides and solve x as a fraction. Remember (9/8)2 = 81/64
Last edited by AshwinUK; 1 week ago
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1 week ago
#6
(Original post by DFranklin)
I think 2. is a separate (and not terribly well laid out) question.
Yeah and I definitely misread it as "found" rather than "find" hence thinking they tried to solve for x and ended up at that stage.
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1 week ago
#7
for the first problem, I think this step usually opens the path for the rest of the solution

More generally, for all surd problems involving nth root, the following realization helps a lot

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