Answer:
b = a + 2 or b = 2 - a
Step-by-step explanation:
Solve for b:
-4 + a^2 + 4 b - b^2 = 0
The left hand side factors into a product with two terms:
(2 + a - b) (-2 + a + b) = 0
Split into two equations:
2 + a - b = 0 or -2 + a + b = 0
Subtract a + 2 from both sides:
-b = -a - 2 or -2 + a + b = 0
Multiply both sides by -1:
b = a + 2 or -2 + a + b = 0
Subtract a - 2 from both sides:
Answer:
b = a + 2 or b = 2 - a
