a.9x(1.7+...)=...x107+9x2.8 b.7.5x(...-4.1)=...x2.25-...x4.1 c....x(3.14-2.17)=0.8x...-0.8x... d.(7.3-3.7)x...=...x0.5+..x0.5

a   .9x(1.7+.2,8..)=.9..x1,7+9x2.8

 b   .7.5x(..2,25.-4.1)=..7,5.x2.25-.7,5..x4.1

 c    ..0,8..x(3.14-2.17)=0.8x3,14...-0.8x.2,17..

 d    .(7.3-3.7)x0,5...=..-3,7.x0.5+7,3..x0.5

a .9x(1.7+.2,8..)=.9..x1,7+9x2.8

 b .7.5x(..2,25.-4.1)=..7,5.x2.25-.7,5..x4.1

 c  .0,8..x(3.14-2.17)=0.8x3,14...-0.8x.2,17..

 d .(7.3-3.7)x0,5...=..-3,7.x0.5+7,3..x0.5