Question

(x+5)square-(x-5)square by identity expand it​

Answer 1

Answer:

(x+5)²—(x-5)²

(a+b)²- (a-b)² =a²+b²+2ab - a²+b²-2ab ( identify 1and 2)

(x+5)²—(x-5)² = x²+5²+2(x)(5) - x²+5²-2(x)(5)

= x²+25+10x - x²+25-10x

= 25+25 (because x² is subtracted with x² and 10 x with 10x so 25 +25 is left )

=50

answer=5O

please mark the brainlest and vote and follow

Answer 2

$\huge\rm\orange{{\underline{answer}}:}$

$\sf{ }$

$\bf{{\underline{To~solve}}:}$

$\tt{~~~~~~~~~~~ (x+5)^{2}-(x-5)^{2}}$

$\sf{ }$

$\bf{{\underline{Method}}:~1}$

$\bf{Identity:~a^{2}-b^{2}=(a+b)(a-b)}$

$\bf{Here:~a=x+5~~and~~b=x-5}$

$\tt{:\implies [(x+5)+(x-5)]×[(x+5)-(x-5)]}$

$\tt{:\implies [x+{\cancel{5}}+x~{\cancel{-5}}]×[{\cancel{x}}+5~{\cancel{-x}}+5]}$

$\tt{:\implies (2x)×(10)}$

$\tt{:\implies {\orange{\underline{\boxed{\bf 20x}}}}}$

$\sf{ }$

$\bf{{\underline{Method}}:~2}$

$\bf{Identity:}$

$\bf{(a+b)^{2}=a^{2}+2ab+b^{2}~~and~~(a-b)^{2}=a^{2}-2ab+b^{2}}$

$\tt{:\implies (x^{2}+10x+25)-(x^{2}-10x+25)}$

$\tt{:\implies {\cancel{x^{2}}}~+10x+~{\cancel{25}}~~{\cancel{-x^{2}}}~+10x~~{\cancel{-25}}}$

$\tt{:\implies 10x+10x}$

$\tt{:\implies {\orange{\underline{\boxed{\bf 20x}}}}}$