2 3/7*7= 4*(2 1/4-1 7/8)=
2 3/7 *7 = 17/7 *7 = 17 4*(2 2/8- 1 7/8 ) = 4* ( 1 10/8-1 7/8)= 4* 2/8 = 1*2/2 = 1
1) 2) -1.5
Спасибо.