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Evaluate 184 2
33866
33856
33836
33806
33856
Use (a−b)2=a2−2ab+b2 for 1842 as (200−16)2. This gives 40000−6400+256=33856.
Number to be squared: 184.
(a+b)2=a2+2ab+b2
Use (a−b)2=a2−2ab+b2 for 1842 as (200−16)2. This gives 40000−6400+256=33856.
Students often make calculation errors in manual multiplication like 184×184 or incorrectly applying (a+b)2 with wrong regrouping.
Represent as binomial
To simplify, express 184 as (200−16).
1842=(200−16)2
Apply expansion formula
Use the algebraic identity (a−b)2=a2−2ab+b2 where a=200 and b=16.
(200−16)2=2002−2×200×16+162
Execute calculation
Calculate each part: 2002=40000, 2×200×16=6400, and 162=256.
40000−6400+256
Final subtraction and addition
Subtract 6400 from 40000 to get 33600, then add 256.
33600+256=33856
B is correct because the square of 184 is 33856.
This identity-based squaring trick is essential for time management in Quant sections and is often used in compound interest calculations.