1) x+5/7=(-3/8)×4/3
x+5/7=(-1/2)
x=(-1/2)-5/7
x=(-7/14)-10/14
x=(-17/14)
2) y-7/12=7/2×(-4/7)
y-7/12=(-2)
y=(-2)+7/12
y=-17/12
3) (-5/14)×21/25-y=15/4
(-3/10)-y=15/4
-y=15/4-(-3/10)
-y=15/4+3/10
-y=75/20+6/20
-y=81/20
y=-(81/20)
0.039*0.002=0.000078
276.35*0.00001=0.00276335
48-11.324=36.676
13910/21.4=650
2.3*0.45=1.035
0,38048/0,0164=23.2