Question

value of 249sqaure - 248 sqaure​

Answer 1

$\bigstar$ Explaination $\bigstar$

⇒$249^2 - 248^2$

$\star$$(a + b)(a - b) = a^2 - b^2$

⇒$(249+248)(249-248) = 249 + 248 = 497$

Extra Information:

i) $(a+b)^2 = a^2 + b^2 + 2ab$

ii) $(a-b)^2 = a^2 + b^2 - 2ab$

iii)$(a+b)(a-b) = a^2 - b^2$

iv) $(a+b)^3 = a^3 + b^3 + 3ab(a+b) = a^3 + b^3 + 3a^2b + 3ab^2$

v)$(a-b)^3 = a^3 - b^3 - 3ab(a-b) = a^3 - b^3 - 3a^2b + 3ab^2$

vi)$a^3 + b^3 = (a+b)(a^2+b^2-ab)$

vii)$a^3 - b^3 = (a-b)(a^2+b^2+ab)$

viii)$(a+b+c)^2 = a^2 + (b+c)^2 + 2a(b+c) = a^2 + b^2 + c^2 + 2(ab+bc+ca)$