Question

How can you express 997 so that the expression ${997}^2$ can be calculated using an algebraic identity?

• A. 990 + 7
• B. 995 + 2
• C. 1000 - 3
• D. 1005 - 8

Answer 1

The correct option is C

1000 - 3

Whenever a number close to a power of 10 is given, we choose the respective power of 10 as the first number.
Here, 1000 will be the first number. This is because ${1000}^2$ is easy to calculate.
The second number will be 3 since 997 is 3 less than 1000.
Thus the expression is 997 = (1000 - 3).