Evaluate using suitable identities53 × 55

1.	Evaluate using suitable identities53 × 55
Answer» 53 × 55 = (50 + 3) (50 + 5) This is in the form. (x + a)(x + b) = x² + (a + b)x + ab Here x = 50, a = 3, b = 5 (50 + 3)(50 + 5) = 50² + (3 + 5)50 + 3 × 5 = 2500 + (8)50 +15 = 2500 + 400 + 15 ∴ 53 × 55 = 2915

Answer»

53 × 55 = (50 + 3) (50 + 5)

This is in the form.

(x + a)(x + b) = x² + (a + b)x + ab

Here x = 50, a = 3, b = 5

(50 + 3)(50 + 5) = 50² + (3 + 5)50 + 3 × 5

= 2500 + (8)50 +15

= 2500 + 400 + 15

∴ 53 × 55 = 2915

Discussion