-3×(-25)=75 а не -75 и значит
75-7=68
Ответ: 68
Х-3.8-2.6=1.5
х-6.4=1.5
х=7.9
-х+3.8-2.6=1.5
-х+1.2=1.5
х=-0.3
-(х-6.4)=1.5
-х+6.4=1.5
х=4.9
-(-х+1.2)=1.5
х-1.2=1.5
х=2.7
7.9-0.3+4.9+2.7=15.2
Ответ:15.2
-5/0 ........................................
(3x+y)(2x-5y)-6(x-y)²=6x²-15xy+2xy-5y²-6(x²-2xy+y²)=
=6x²-13xy-5y²-6x²+12xy-6y²=6x²-6x²-13xy+12xy-5y²-6y²=
=-xy-11y²