5 7/4=6 3/4
4 5/9= 3 14/9
8=7 5/5
(н+87)-130=200
н+87=330
н=330-87
н=243
ОТВЕТ:243
-3(x-5y)+5(x+3y)=-3x+15y+5x+15y=2x+30y=2(x+15y)
1)6цел2/3+2цел4/15=8цел14/15
2)8цел14/15+5цел1/2=13цел28+15/30=13цел43/30=14цел13/30
3)433/30:1/15=433/30:2/30=433/30*30/2=433/2=216цел1/2