Ⅰ. x 2 = 729 Ⅱ. y = √ 729

According to question ,we have
From equation Ⅰ. x² = 729
⇒ x = ± √729 = ± 27
From equation Ⅱ. y = √729
⇒ y = 27
Hence , x ≤ y is required answer .