( (x-y) / (x) - (y-x) / (y) ) / ( (x+y) / (yx) ) =
= ( (x-y) / (x) - (y-x) / (y) ) * ( (yx) / (x+y) ) =
= ( ( y(x-y) - x(y-x) ) / (xy) ) * ( (yx) / (x+y) ) =
= ( y(x-y) + x(x-y) ) / ( x+y ) = ( (y+x)(x-y) ) / ( x+y ) = x-y
8*4+2=34
8:4:2=1
8+(4:2)=10
8*4-2=30
8:4+2=4
8*4*2=64
8+4+2=14
8*(4+2)=48
16 * 50 = 800
(площадь)
800 * 60% = 800 * 0.6 = 480
(Ответ)