\(a,2,7+\left(1,4-0,3\right)-\left(2,7+1,4\right)\\ =2,7+1,4-0,3-2,7-1,4\\ =\left(2,7-2,7\right)+\left(1,4-1,4\right)-0,3\\ =0+0-0,3\\ =-0,3\)
\(b,\left(3,4-1,5\right)-\left(1+3,4\right)+1,=3,4-1,5-1-3,4+1,5\\=\left(3,4-3,4\right)-\left(1,5-1,5\right)-1\\ =0-0-1\\ =-1\)
a) 2,7 + (1,4 - 0,3) - (2,7 + 1,4)
= 2,7 + (1,1) - ( 4,1)
= 2,7 + -3
= -0,3