Answer:
7. A = 40.8 deg; B = 60.6 deg; C = 78.6 deg
8. A = 20.7 deg; B = 127.2 deg; C = 32.1 deg
Step-by-step explanation:
Law of Cosines

You know the lengths of the sides, so you know a, b, and c. You can use the law of cosines to find C, the measure of angle C.
Then you can use the law of cosines again for each of the other angles. An easier way to solve for angles A and B is, after solving for C with the law of cosines, solve for either A or B with the law of sines and solve for the last angle by the fact that the sum of the measures of the angles of a triangle is 180 deg.
7.
We use the law of cosines to find C.






Now we use the law of sines to find angle A.
Law of Sines

We know c and C. We can solve for a.


Cross multiply.





To find B, we use
m<A + m<B + m<C = 180
40.8 + m<B + 78.6 = 180
m<B = 60.6 deg
8.
I'll use the law of cosines 3 times here to solve for all the angles.
Law of Cosines



Find angle A:





Find angle B:





Find angle C:





Let x be a random variable representing the price of a Congo-imported black diamond. Let the higher price be p. Then,
P(x < p) = P(x < (p - mean)/sd) = P(x < (p - 60,430)/21,958.08) = P(z < 2)
Therefore,
(p - 60,430)/21,958.08 = 2
p - 60,430 = 2 x 21,958.08 = 43,916.16
p = 34,916.16 + 60,430 = 104.346.16
Therefore, The required price is $104,346.16
Step-by-step explanation:

Answer:
Explanation:
We have:
(
2
x
+
3
)
(
4
x
2
−
5
x
+
6
)
Now let's distribute this piece by piece:
(
2
x
)
(
4
x
2
)
=
8
x
3
(
2
x
)
(
−
5
x
)
=
−
10
x
2
(
2
x
)
(
6
)
=
12
x
(
3
)
(
4
x
2
)
=
12
x
2
(
3
)
(
−
5
x
)
=
−
15
x
(
3
)
(
6
)
=
18
And now we add them all up (I'm going to group terms in the adding):
8
x
3
−
10
x
2
+
12
x
2
+
12
x
−
15
x
+
18
And now simplify:
8
x
3
+
2
x
2
−
3
x
+
18Step-by-step explanation:
It is False.
If a property is commutative in subtraction it means: x - y is the same as y - x.
For example 5 - 3 = 2, but 3 - 5 = -2 so subtraction is not commutative.
But 5 + 3 = 8 , is the same as 3 + 5 = 8.
Addition is Commutative, but Subtraction is not commutative.
So the statement that subtraction of whole numbers is commutative is False.