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.