2/7 х (-5 1/4)= 3,6 х (-2/3)= -2,8 х (-1 1/7)=
2/7 х (-5 1/4)= - 3/2 = - 1 1/2
3,6 х( - 2/3) =- 12/5 = - 2 2/5
-2,8 х(-1 1/7) = 16/5 = 3 1/5
2/7 х (-5 1/4)= 2/7 * (-21/4) =2*(-21)/7*4=-42/28= -3/2= - 1 1/2
3,6 х (-2/3)= 3 6/10* (-2/3)= 36/10* (-2/3)= - 2*36/ 10*3= -72/30= -36/15= -12/5= -2 2/5
-2,8 х (-1 1/7)= -2 8/10*(-8/7)= -28/10*(-8/7)= -14/5* (-8/7)= 14*8 /5*7= 112/35= 16/5= 3 1/5