Question

Find the value of :-(a) (89)² (b) (999)²

Answer 1

Answer:

Step-by-step explanation:

(90 - 1) sq.

90 sq - 2×90×1 + 1 sq

8100 - 180 + 1

7921

Answer 2

Answer:

(a) 7921 (b) 998001

Step-by-step explanation:

(89)²

Write in the format (a - b)²:

= (90 - 1)²

Apply (a - b)² = a² - 2ab + b²:

= (90)² - 2(90)(1) + (1)²

Evaluate each term:

= 8100 - 180  + 1

Combine the terms:

= 7921

------------------------------------------------------------

(999)²

Write in the format (a - b)²:

= (1000 - 1)²

Apply (a - b)² = a² - 2ab + b²:

= (1000)² - 2(1000)(1) + (1)²

Evaluate each term:

= 1000000 - 2000  + 1

Combine the terms:

= 998001

Answer: (a) 7921 (b) 998001