1) 7m+2-(4-3,5m)=? 2) 5(3-1,4b)+2 (3b-11)=? 3) 15axy-10ay+20xy=?

1) 7m + 2 - (4 - 3,5m) = 7m + 2 - 4 + 3,5m = 10,5m - 2
2) 5(3 - 1,4b) + 2(3b - 11) = 15 - 7b + 6b - 22 = - b - 7
3) 15ayx - 10ay + 20xy = 5y(3ax - 2a + 4x)