Answer:
y = mx + b
Step-by-step explanation:
y represents the dependent variable (value you are getting).
m represents the slope of the line.
x represents the independent variable (what you are changing).
b represents the y-intercept, or the y value when x is zero.
Answer: 15
Step-by-step explanation: Use the formula: 
Remember
should always be the hypotenuse or the longest side.
---> evaluate the exponents
----> subtract 12544 to the other side
---> take the square root of both sides

The answer is C. 90 degrees.
This is because angle R is one of the four angles of a square.
I hope this helps.