Question

find the value of the followimg using suiyable properties
$3998 \times 765 + ( - 2998) \times 765$
​

Answer 1

Answer:-

$\sf{The \ value \ of \ 3998\times765+(-2998)\times765}$

$\sf{is \ 765000.}$

Given:

• 3998×765+(-2998)×765

Solution:

$\boxed{\sf{an+bn=(a+b)n}}$

$\sf{\implies{3998\times765+(-2998)\times765}}$

$\sf{\implies{(3998-2898)\times765}}$

$\sf{\implies{1000\times765}}$

$\sf{\implies{765000}}$

$\sf\purple{\tt{\therefore{The \ value \ of \ 3998\times765+(-2998)\times765}}}$

$\sf\purple{\tt{is \ 765000.}}$

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$\sf\blue{Extra \ identities}$

$\sf{(a+b)^{2}=a^{2}+2ab+b^{2}}$

$\sf{(a-b)^{2}=a^{2}-2ab+b^{2}}$

$\sf{(a+b)(a-b)=a^{2}-b^{2}}$

$\sf{(a+b+c)^{2}=a^{2}+b^{2}+c^{2}+2(ab+bc+ca)}$

$\sf{(a+b)^{3}=a^{3}+3a^{2}b+3ab^{2}+b^{3}}$

$\sf{(a-b)^{3}=a^{3}-3a^{2}b+3ab^{2}-b^{3}}$