All in all you would get the answer x+y=1.
No you can not copy and paste a picture of a problem i believe
Answer:
D) 
Step-by-step explanation:
A)

B)

C)

D)

Answer:
x=45
Step-by-step explanation:
An entire triangle is 180 degrees and you already know that one angle is 90 degrees. 180 - 90 is 90. Now you have the equation 2x=90.
You then divide each side by 2 to get the x by itself which leaves you with x=45.
An example of the ratio 4:1 could be, in a school for every 4 girls there is 1 boy. Or something similar:)