What expressions are equivalent to y4 - 625?
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Answer:
option D
Step-by-step explanation:
a² - b² = (a + b) (a - b)
625 = 5 * 5 * 5 * 5 = 5⁴
y⁴ - 625 = y⁴ - 5⁴
= (y²)² - (5²)² {a = y² ; b = 5²}
= (y² + 5²)(y² - 5²)
= (y² + 25)(y² - 5²)
= (y² + 25)(y + 5)(y - 5)