SVP petit calcul besoin aide

1)
A = 13/25 - 27/25 : 8/5 + 6/11 x 1/10
A = 3/25 - 27/25 x 5/8 + 6/110
A = 3/25 - 135/200 + 6/110
A = 3 x 8 / 25 x 8 - 135/200 + 6/110
A = 24/200 - 135/200 + 6/110

2)
A = - 111/200 + 6/110
A = - 111 x 110 / 200 x 110 + 6 x 200 / 110 x 200
A = - 12210/22000 + 1200/22000
A = - 11010/22000
A = 10 x 1101 / 10 x 2200
A = 110/2200

fraction irreductible1/20