For number 15 and 16, you just have to find the absolute difference between the two points along the calibration of the protractor.
15. ∠BXC = |B - C| = |140° - 110°| = 30°
16. ∠BXE = |B - E| = |140° - 30°| = 110°
For numbers 20 and 21, apply the Angle Addition Postulate. This is when you add the individual interior angles to equate to the total angle.
20. ∠PQS = ∠PQR + ∠RQS
112° = 72°+ 10x°
x = 4
21. ∠KLM = ∠KLN + ∠NLM
135° = 47°+ 16y°
y = 5.5
Answer:
The value of the Rational expression when
is: 
Step-by-step explanation:
For this exercise is important to remember:
- When a negative number is raised to an even power, the result will be positive.
- The multiplication of signs:

Then, given the following Rational expression:

You need to follow these steps in order to find its value when
:
1. Substitute the given value of "x" (
) into the expression:

2. Evaluate and simplify:

Answer:
8:25
Step-by-step explanation:
Theres 8 biography books and 25 books in total. 8:25
:D
Answer:
0.783
Step-by-step explanation:
To find first r and then r square for the data
correlation coefficient of x and y = Cov (x,y)/std dev x * std dev Y
Cov (x,y) = E(xy) -E(x)E(y)
Hence calculations would be as follows:
x y xy
1 2 2
2 10 20
5 5 25
7 18 126
10 25 250
Mean 5 12 84.6
Cov E(xy)-E(x)E(y) 24.6
r 0.884640297
r^2 0.782588454
so answre is 0.783 after rounding off.
Area of a semi circle = pi * radius^2 / 2
3.14 * 5^2 / 2
3.14 * 25 / 2
78.5 / 2
39.5
Area of a rectangle = length * width
16 * 10
160
Add both of the areas
39.5 + 160
C. 199.5