How do i solve this using imaginary numbers? PLEASE HELP

14 -2i

Step-by-step explanation:

9 + sqrt(-4) - ( -5 + sqrt(-16))

We know the sqrt of a negative number is i * sqrt(number)

9 + isqrt(4) - ( -5 + isqrt(16))

9 + 2i - (-5 + 4i)

Distribute the negative sign

9+2i +5 -4i

Combine like terms

14 -2i

(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