Respuesta :

znk

Answer:

1) -5 and +5; 2) -9 and +9

Step-by-step explanation:

1) a² + 2ab + b² = 25

(a + b)² = 25      Wrote the left-hand side as a square

  a + b =  ±5    Took the square root of each side

All values of a + b are -5 and +5.

2) a² − 8ab + 16b² = 81

(a - 4b)² = 81      Wrote the left-hand side as a square

  a - 4b = ±9     Took the square root of each side

All values of a - 4b are -9 and +9.