Question

1. (3,9-5,8)-(-1/45-7/9)+1,1 2. (1/30-5/6)-(-3,9-2,2)-5,3

Answer 1

$1)3,9-5,8=-1,9 \\ 2)-1,9+1,1=-0.8 \\ 3) \frac{1}{45} + \frac{7}{9} = \frac{1+35}{45} =\frac{36}{45} =\frac{4}{5} \\ 4)-0,8+ \frac{4}{5} =-0,8+0,8=0 \\ \\ \\ 1) \frac{1}{30} - \frac{5}{6} = \frac{1-25}{30} =- \frac{24}{30} =- \frac{4}{5} \\ 2)3,9+2,2=6,1 \\3) 6,1-5,3=0,8 \\ 4)- \frac{4}{5} +0,8=-0,8+0,8=0$

Answer 2

To solve these expressions, let's break them down step by step:

1. $(3.9 - 5.8) - \left(-\frac{1}{45} - \frac{7}{9}\right) + 1.1$

   $= (3.9 - 5.8) - \left(-\frac{1}{45} - \frac{7}{9}\right) + 1.1$

   $= -1.9 - \left(-\frac{1}{45} - \frac{7}{9}\right) + 1.1$

   $= -1.9 + \frac{1}{45} + \frac{7}{9} + 1.1$

   $= -1.9 + 0.0222 + 0.7778 + 1.1$

   $= -0.1 + 1.9$

   $= 1.8$

2. $\left(\frac{1}{30} - \frac{5}{6}\right) - \left(-3.9 - 2.2\right) - 5.3$

   $= \left(\frac{1}{30} - \frac{5}{6}\right) - \left(-3.9 - 2.2\right) - 5.3$

   $= \left(-\frac{5}{6} + \frac{1}{30}\right) - \left(-6.1\right) - 5.3$

   $= \left(-\frac{25}{30} + \frac{1}{30}\right) + 6.1 - 5.3$

   $= -\frac{24}{30} + 6.1 - 5.3$

   $= -\frac{4}{5} + 0.8 - 5.3$

   $= -0.8 - 5.3$

   $= -6.1$

So, the solutions are:

1. $1.8$
2. $-6.1$