Question

13.1²-2.5² find using suitable identity

Answer 1

Using identity of
$a {}^{2} - b {}^{2} = a {}^{2} - 2 \times a \times b + b {}^{2}$
$13.1 {}^{2} - 2.5 {}^{2} = 13.1 {}^{2} - 2 \times 13.1 \times 2.5 + 2.5 {}^{2}$
$13.1 {}^{2} - 2.5 {}^{2} = 171.21 - 65.5 + 6.25$
$13.1 {}^{2} - 2.5 {}^{2} = 171.41 - 71.75$
$13.1 {}^{2} - 2.5 {}^{2} = 99.66$
Hope you shall understand that.Thank you!