Answer:
6=x
Step-by-step explanation:
Recall that
where 
is the angle between the vectors 
whose magnitudes are 
, respectively.
We have
Answer:
Then, a=-1 and b=-1
Step-by-step explanation:
We need to solve the following system of equations using the adition method:
2a+3b=-1 (i)
3a+5b=-2 (ii)
First, we multiply the equation (i) by -3 and the equation (ii) by 2, so we get:
-6a-9b=3
6a+10b=-4
Adding the two equations we have:
-6a-9b=3
6a+10b=-4
--------------------------
0 + b = -1
Then b=-1. Now, let's substitute the value of b into equation (i):
2a+3b=-1
2a + 3(-1) = -1
2a -3 = -1
2a = 2
a = 1
Then, a=-1 and b=-1
Answer:
Labrador retrievers
Step-by-step explanation:
We know that the mean 
is:
and the standard deviation 
is:
The probability that a randomly selected Labrador retriever weighs less than 65 pounds is:
We calculate the Z-score for X =65
So
Looking in the table for the standard normal distribution we have to:
.
Finally the amount N of Labrador retrievers that weigh less than 65 pounds is:
Labrador retrievers
1 Move all terms to one side.
{x}^{2}+15x+45=0
x
2
+15x+45=0
2 Use the Quadratic Formula.
x=\frac{-15+3\sqrt{5}}{2},\frac{-15-3\sqrt{5}}{2}
x=
2
−15+3
5
,
2
−15−3
5
3 Simplify solutions.
x=-\frac{3(5-\sqrt{5})}{2},-\frac{3(5+\sqrt{5})}{2}
x=−
2
3(5−
5
)
,−
2
3(5+
5
)
