Operations with Signed Numbers: Very Difficult Problems with Solutions

Solution:
m - (m - n) : (-2) ⋅ (-5) = (-4) - [-4 - (-6)] : (-2) ⋅ (-5) = -4 - 2 : (-2) ⋅ (-5) = -4 - (-1) ⋅ (-5) = -4 - (+5) = -9

Solution:
Evaluate the expression
[x : (y - 3)] ⋅ (-4) - [xy + (-3)] : -1 =
[(-5) : (-2 - 3)] ⋅ (-4) - [(-5) ⋅ (-2) + (-3)] : -1 =
[(-5) : (-5)] ⋅ (-4) - [10 + (-3)] : -1 =
(+1) ⋅ (-4) - (+7) : -1 = -4 - (-7) = -4 + 7 = 3

Solution:
[tex][2.4 - (0.3 - 0.21) \cdot 2 + 0.44 : (-2)]:\frac{4}{5} =[/tex]
[tex][2.4 - 0.09 \cdot 2 + (-0.22)]:\frac{4}{5} =[/tex]
[tex](2.4 - 0.18 - 0.22):\frac{2}{5} = 2 : \frac{4}{5} = \frac{5}{2} = 2.5[/tex]

Solution:
[tex]3:\left(-\frac{3}{5}\right)-\left(-\frac{4}{5}:2\right)+5\cdot \left[-0.4 - \frac{4}{10}:(-2)\right] = [/tex]
[tex]-5+\frac{2}{5}+5\cdot \left(-0.4 + \frac{1}{5}\right) = [/tex]
[tex]-5+0,4+5\cdot \left(-0.4 + 0.2\right) = [/tex]
[tex]-4.6+5\cdot (- 0.2) = -4.6 - 1 = -5.6[/tex]