mean = (sum of values) / (number of values)
we know mean is 13 and we are given 8 values. The ninth value is the missing x:
13 = ((sum of 8 values) + x)/9
13 = (12+10+15+12+13+15+11+15+x)/9
13*9 = 103+x
x = 14
The missing value is 14. There are 14 pillows in the last box.
Answer:
36-A
9-B
Step-by-step explanation:
For this case we have the following polynomial:

We must find the greatest common factor of the terms of the polynomial.
The GCF of the coefficients is given by:

Then we look for the GFC of the variables:
We have then:

Finally rewriting we have:

Answer:
the complete factored form of the polynomial is:

Answers: ∠a = 30° ; ∠b = 60° ; ∠c = 105<span>°.
</span>_____________________________________________
1) The measure of Angle a is 30°. (m∠a = 30°).
Proof: All vertical angles are congruent, and we are shown in the diagram that angle A — AND the angle labeled with the measurement of 30°— are vertical angles.
2) The measure of Angle b is 60°. (m∠b = 60<span>°).
Proof: All three angles of a triangle add up to 90 degrees. In the diagram, we can examine the triangle formed by Angle A, Angle B, and a 90</span>° angle. This is a right triangle, and the angle with 90∠ degrees is indicated as such (with the "square" symbol). So we know that one angle is 90°. We also know that m∠a = 30°. If there are three angles in a triangle, and all three angles must add up to 180°, and we know the measurements of two of the three angles, we can solve for the unknown measurement of the remaining angle, which in this case is: m∠b.
90° + 30° + m∠b = 180<span>° ;
</span>180° - (<span>90° + 30°) = m∠b ;
</span>180° - (120°) = m∠b = 60<span>°
</span>___________________________
Now we need to solve for the measure of Angle c (<span>m∠c).
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All angles on a straight line (or straight "line segment") are called "supplementary angles" and must add up to 180</span>°. As shown, Angle c is on a "straight line". The measurement of the remaining angle represented ("supplementary angle" to Angle c is 75° (shown on diagram). As such, the measure of "Angle C" (m∠c) = m∠c = 180° - 75° = 105°.