First, do 0.4 + 0.4. So, you can see what number you should get when you check your answer. For this, you should get 0.8
Then, do 0.8 + 1.6
After you add those 0.8 and 1.6, you should get your answer.
To check your answer, plug in your answer where B is and see if you get 0.8. I hope this helps! I did as much explaining as I could! If you need anymore help with this, just comment
The answer: x is equal to 50



now, with that template above in mind, let's see this one

A=3, B=1, shrunk by AB or 3 units, about 1/3
C=2, horizontal shift by C/B or 2/1 or just 2, to the left
D=4, vertical shift upwards of 4 units
check the picture below
2 3/5 or 2 6/10 is the answer