(2 3//4 + 2 1//5) * 16

разве не 79?

да, спасибо, 4 упустил

:-)

(2 3/4+2 1/5)*16=(2 15/20+2 4/20)*16=4 19/20 * 16=4*16 + 19/20*16=56+(19*4)/5=56+76/5=56+25 1/5=79 1/5

(2 3//4 + 2 1//5) * 16 = 1) 2 3/4 + 2 1/5 = 4 (15 + 4)/20 = 4 19/202) 4 19/20 * 16 = 99/20 * 16 = 396/5 = 79 1/5