Peter bought 3 biscuits for 1.59 each and 3 sausages for 2.50 each at the corner restaurant he left a 1.85 tip for the server how much did peter have left from the 25 he took to the restaurant

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225