A quick question...

[elfin topaz]

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[vernal shadow]

do you have any idea where to start?

[thorn bay]

Is it sqrt(5/2) or sqrt(5)/2 ?

[vernal shadow]

its 9(a)

well you need some factor of sqrt 5 to cancel out the 3(sqrt5), but you also need a perfect square as a factor so the 2 doesnt have a sqrt

try to find from here

[thorn bay]

You can use surds perhaps?

[vernal shadow]

actually

just use difference of squares

[thorn bay]

Find the squares of 3 and multiply it with 5. Make sure to draw the sqrt symbol on it

Sqrt(45)

Eugh that's irrational

[vernal shadow]

difference of squares easiest way

if you know what that is

[vast ocean]

to rationalize denominator multiply by the conjugate, that is, to remove a + b*sqrt(c) from the denominator, multiply it and the numerator by a - b*sqrt(c)