Y=145
Explanation:
A triangle’s angles add up to a total of 180 so you would subtract 55 from 180 and then subtract 90 because of the right angle, then you would end with x=35. Since x and y are supplementary they add to 180...so then you subtract 35 from 180 and then you get y=145.
For this case we must simplify the following expression:

We solve the operation of the second parenthesis, taking into account that different signs are subtracted and the sign of the major is placed:

We multiply:

We eliminate the parentheses:

We add similar terms, taking into account that equal signs are added and the same sign is placed:

Answer:
The simplified expression is: 
Answer:

Step-by-step explanation:
Simply:

It is simple, you are converting 150 of 200 into a fraction and reducing it
150/200=15/20
5 goes into 20 4 times
15/20=1/4
1/4=0.75=75%