Evaluate the i 30 + i 40 + i 60

Show that 1 + i¹⁰ + i²⁰ + i³⁰ is a real number?

Solve the quadratic equations by factorization method only 6x² – 17ix – 12 = 0

Solve the quadratic equations by factorization method only x² + (1 – 2i)x – 2i = 0

Solve the quadratic equations by factorization method only x² + 10ix – 21 = 0

Solve the quadratic equations by factorization method only 17x² – 8x + 1 = 0