The square of a binomial expands as follows:

Expanding all the binomials, we have

Sum like terms:

Simplify terms appearing on both sides:

Move all terms involving k to the left and all numbers to the right:

Divide both sides by -20:

Answer:24
Step-by-step explanation: If she bought x amount of posters and had 12 left after, you'd multiply 12 by 2 and get 24. Half of 24 is 12. So Micaela bought 24 posters.
Answer:
Step-by-step explanation:
Prime factorization requires dividing by primes starting with smallest prime number
402/2=201
201/3=67, 67 is prime so we cannot go further so the prime factorization of 402 is
2X3X67