X/10+1.7=-3.5

Question

X/10+1.7-1.7=-3.5-1.7
X/10=-5.20
X/10 . 10/1= 5.20 . 10

Why is the answer -52?

Answer 1

Because X/10 = -5.2, which you already correctly derived.
The last step is to multiply both sides of the equation by 10.