Question

which of the following expressions is equivalent to the expression 945 × 855
(a) 900²+(45+55)900+(45×55)
(b) 900²+45²
(c) 800²+(45+55)800+45×55
(d)900²+45²​

Answer 1

$Given \: expression : 945 \times 855$

$= ( 900 + 45 )( 900 - 45 )$

$= 900^{2} - 45^{2}$

/* By Algebraic Identity */

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

/* Given options are wrong */

Therefore.,

$\red{ 945 \times 855} \green { = 900^{2} - 45^{2}}$

•••♪

Answer 2

$\huge \: answer : \\ \\ 945 \times 855 = (900 + 45)(900 - 45) \\ \\ (a + b)(a - b) = {a}^{2} - {b}^{2} \\ \\ (900 + 45)(900 - 45) = {900}^{2} - {45}^{2}$

$\blue{required \: \: answer \: \: is \: \: {900}^{2} - {45}^{2} }$

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