1)87:(4x+5)=3
4x+5=87:3
4x+5=29
4x=24
x=6
2)17(3x-16)=85
3x-16=85:17=5
x=21:3
x=7
<span>(5\6)*( 3\10 +1 1\2)= (5\6)*( 0,3+1,5) = (5\6)*1,8 = (5\6)*(18/10)=9/6=3/2=1,5
(5\8+3\4)*( 1 5\11 )=(11/8)**(16\11 ) =16/8<span> =2</span></span>
...............................