Ответ:(x- \frac {5x}{x+2}): \frac {x-3}{x+2}=\frac {x*(x+2)-5x}{x+2}: \frac {x-3}{x+2}=\\\\=\frac {x^2+2x-5x}{x+2}: \frac {x-3}{x+2}=\frac {x^2-3x}{x+2}* \frac {x+2}{x-3}=\\\\=\frac {x(x-3)*(x+2)}{(x+2)(x-3)}=x
Объяснение:
(sina+sinb)^2+(cosa+cosb)^2=sina^2+2sina*sinb+sinb^2+cosa^2+2cosa*cosb+cosb^2=<span>=1+1+2sina*sinb+2cosa*cosb=2+2cos(a-b)=2(1+cos(a-b))</span>
Log12(1/2*1/72)=log12(1/144)=log12(12^-2)