Show that (4+√12)(5-√3)= 14+6√3

First, expand out the brackets. Initially, this will give you 20 - 4√3 + 5√12 - √36.

√36 is the equivalent of 6, now giving up 20 - 4√3 + 5√12 - 6. We can combine the 20 and the 6 to give us 14 - 4√3 + 5√12.

Now, let's look at 5√12. √12 is the same as √4 x √3. √4 is the same as 2, so we have 2√3. We then substitute in 2√3 as √12, giving us 5(2√3). This then becomes 10√3.

We then have 14 - 4√3 + 10√3. We can then do 10√3 - 4√3, which gives us 6√3.

Altogether, this gives us our answer of 14 + 6√3!

LH

Related Maths GCSE answers

All answers ▸

I keep making silly mistakes how do I stop that?


Write x^2 + 8x + 7 in the form (x + a)^2 + b


Adam gets a bonus of 30% of £80. Katy gets a bonus of £28. Work out the difference between the bonus Adam gets and the bonus Katy gets.


Find the solutions of the equation x^2 - 2x - 8 =0