Answer:
X=1550-10y
Step-by-step explanation:
X+10y=1550
Subtract 10y from each side
X+10y- 10y=1550-10y
X=1550-10y
49/100 in simply that is your answer
Here's a diagram showing how to combine angles LDA (in red) and angle ADE (in blue). Hopefully it becomes a bit clearer why these two angles add up to line segment LE. Erase the shared segment DA if it helps show LE better.
See attached image below.
C is the answer. A and D are reflections and b is a translation