1. 3,5a²b³a³b⁴c*(-2/7)abc³
-1a(6)b(8)c⁴
2.а)3,5x³-2,5x³=x³
б)1/7ab+2/3ab=3/21ab+14/21ab=17/21ab
3. 3x²y-2xy²+xy-3x²y+xy²+3xy
-xy²+4xy
4.x:3a²bc(5)=-17a³b⁴c
x=-17a³b⁴c*3a²bc(5)
x=-51a(5)b(5)c(6)
-51a(5)b(5)c(6):3a²bc(5)=-17a³b⁴c
6.315x(7)y(39)z¹²:15x(6)y(39)z(7)=21xz(5)
7.
27a(6)b²c⁴:x=3a⁴b²c
x=27a(6)b²c⁴:3a⁴b²c
x=9a²c³
27a(6)b²c⁴:9a²c³=3a⁴b²c