Question

7.reduzca:(m+5)^2-(m-5)^2 entre 10m

Answer 1

[(m+5)^2-(m-5)^2)]/10m=
[(m^2+10m+25)-(m^2-10m+25)]/10m=
(m^2+10m+25-m^2+10m-25)/10m=
[(m^2-m^2)+(10m+10m)+(25-25)]/10m=
[(0)+(20m)+(0)]/10m=
20m/10m=
2

Answer 2

La identidad de Legendre.

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

$(a + b)^{2} - (a - b)^{2}= 4ab$

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Usamos el segundo método.

$\frac{(m+5)^{2}-(m-5)^{2}}{10m}$

$\frac{4(m)(5)}{10m}$

$\frac{20m}{10m}$

$2m$ <== respuesta.