Can anyone help with these two questionsWatch
2. find x as a fraction of 2x^½=9/8
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.
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
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
More generally, for all surd problems involving nth root, the following realization helps a lot