1) -5/6 + 3/8=-20\24+9\24=-11\24
2) -2 5/7 - 1 3/14=-2 10\14-1 3\14=-3 13\14
<span>(6/35-4/7)-(-1,8-4,3)-5,7=0
1)6\35-4\7=6\35-20\35=-14\35=-2\5=-0.4
2)-1.8-4.3=-6.1
3)-0.4-(-6.1)=-0.4+6.1=5.7
4)5.7-5.7=0</span>
12, 24, 36, 48, 60, 72, 84, 96, 108, 120
1) 72/ (13-11)(13+11)= 72/(2)(24)=72/48=1.5
2) (79-65)(79+65)/420=(14)( 144)/420=144/30=4.8
3) (92-48)(92+48 )/ (27+17)(27-17)= (44*140)/(44*10)=14
4)(63-27)(63+27)/ (83-79)(83+79)=(36*90)/(4*162)=5