Answer:
8
Step-by-step explanation:
Two different approaches:
Method 1
Apply radical rule √(ab) = √a√b to simplify the radicals:
√98 = √(49 x 2) = √49√2 = 7√2
√50 = √(25 x 2) = √25√2 = 5√2
Therefore, (√98 - √50)² = (7√2 - 5√2)²
= (2√2)²
= 4 x 2
= 8
Method 2
Use the perfect square formula: (a - b)² = a² - 2ab + b²
where a = √98 and b = √50
So (√98 - √50)² = (√98)² - 2√98√50 + (√50)²
= 98 - 2√98√50 + 50
= 148 - 2√98√50
Apply radical rule √(ab) = √a√b to simplify radicals:
√98 = √(49 x 2) = √49√2 = 7√2
√50 = √(25 x 2) = √25√2 = 5√2
Therefore, 148 - 2√98√50 = 148 - (2 × 7√2 × 5√2)
= 148 - 140
= 8
