Question

Find the squares of the following numbers using the column method:
(c) 42
​

Answer 1

Answer:

Solution:

We know that

\begin{gathered}( {a + b)}^{2} = {a}^{2} + 2ab + {b}^{2} \\ \\ here \\ 42 = 40 + 2 \\ \\ {(40 + 2)}^{2} = ( {40)}^{2} + 2(40)(2) + {2}^{2} \\ \\ = 1600 + 160 + 4 \\ \\ ( {40)}^{2} = 1764 \\ \\\end{gathered}

(a+b)

2

=a

2

+2ab+b

2

here

42=40+2

(40+2)

2

=(40)

2

+2(40)(2)+2

2

=1600+160+4

(40)

2

=1764

put those values in the column,while writing the answer

Hope it helps you.