Hi,
Equation:
[tex] \frac{1}{2} x -  \frac{2}{5} x =  - 2[/tex]
Solving:
[tex] \frac{1}{2}x -  \frac{2}{5} x =  - 2  \:  \:  \: |  \times 10 \\  10  \times  \frac{1}{2} x - 10 \times  \frac{2}{5} x =  - 10 \times 2 \\ 5x - 2 \times 2x =  - 20 \\ 5x - 4x =  - 20 \\ x =  - 20 \:  \:  \:  \:  \:  \:  result[/tex]
Hope this helps.
r3t40