Question

Решите уравнение::пож..

Answer 1

$(c+d)(d-c)=(d+c)(d-c)=d ^{2} -c ^{2} \\ c=2;d=4 \\ \\ 4 ^{2} -2 ^{2} =16-4=12 \\ \\ \frac{81*3}{3 ^{2} } = \frac{81*3}{9} =9*3=27 \\ \\ \frac{81*3}{3 ^{2} } = \frac{3 ^{4}*3 ^{1} }{3 ^{2} } =3 ^{4+1-2} =3 ^{3} =27$