We rewrite 79 as 80 – 1 to use the subtraction square identity with a = 80 and b = 1. Combining their squared values and subtracting the double product gives 6241.
Using the identity (a – b) square = a square – 2ab + b square, find the value of (79) square
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To calculate this square easily without direct vertical multiplication, we express 79 as 80 – 1. This lets us use the subtraction square identity where a is 80 and b is 1. The square of 80 is 6400, and the square of 1 is 1. The middle term to subtract is two times 80 times 1, which is 160. Computing 6400 minus 160 plus 1 gives 6241.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 4 Exploring Algebraic Identities (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-4/