In this question x * y means if x < y, and if x is larger or equal to y.

a) Find the value of

i) 5 * 8

So x = 5 and y = 8. Clearly, x<y, so just substitute the values 'x=5' and 'y=8' into the first equation to give:

This simplifies to give an answer of 7.

Can you apply this to part ii)?

Then for part b) iii)

We know that y=7 and the answer is 8. Substituting that into the original equation:

Gives:

As this value of x is greater than our value of y, however, this is incorrect as we can only use this equation 'if x < y'

So you'll have to substitute the values into the second equation.

Can you apply this to part ii?

FInally, part c. I don't understand part c as it seems to me that there could be almost infinite values for that equation. Is it not just trial and error?