Answer:
x = 5 OR x = 0. Either answer would be correct, but they may not give u the mark if you don't put both, so write like how i've done.
Explanation:
lets call unnamed number x.
so we know that x is 1/15 of x², or x = x²/15
that means that x² = 15x (rearranged)
rearrange to the form of ax² + bx + c = 0 (quadratic formula):
x² - 15x = 0
Factorise or use quadratic formula (factorised form shown):
(x - 5)(x ± 0) = 0 , which gives the x values to be:
x = 5 OR 0