Answer:
B
Step-by-step explanation:
Let's create an equation in point-slope form, which is:
, where
is the point and m is the slope.
Here, our point is (-2, 7) and our slope is m = -5 so plug these in:


Now, if (a, 2) lies on this line, then it should satisfy the equation. So plug in a for x and 2 for y:
2 - 7 = -5(a + 2)
-5 = -5(a + 2)
Divide by -5:
1 = a + 2
Subtract 2 from both sides:
a = -1
Thus, the answer is B.
Hope this helps!
96.67 is the mean of these 3 numbers
Answer:

Step-by-step explanation:
Given:


Need:

First, let's look at the identities:
sum: 
difference: 
The question asks to find sin(A - B); therefore, we need to use the difference identity.
Based on the given information (value and quadrant), we can draw reference triangles to find the simplified values of A and B.
sin(A) = 
cos(A) = 
sin(B) = 
cos(B) = 
Plug these values into the difference identity formula.


Multiply.

Add.

This is your answer.
Hope this helps!
Answer:
Eq: (x+a/2)²+(y+1)²=(a²-8)/4
Center: O(-a/2, -1)
Radius: r=0.5×sqrt(a²-8)
Mandatory: a>2×sqrt(2)
Step-by-step explanation:
The circle with center in O(xo,yo) and radius r has the equation:
(x-xo)²+(y-yo)²=r²
We have:
x²+y²+ax+2y+3=0
But: x²+ax=x²+2(a/2)x+a²/4-a²/4= (x+a/2)²-a²/4
And
y²+2y+3=y²+2y+1+2=(y+1)²+2
Replacing, we get:
(x+a/2)²-a²/4+(y+1)²+2=0
(x+a/2)²+(y+1)²=a²/4-2=(a²-8)/4
By visual inspection we note that:
- center of circle: O(-a/2, -1)
- radius: r=sqrt((a²-8)/4)=0.5×sqrt(a²-8). This means a²>8 or a>2×sqrt(2)
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$25.34 < $85.00 < $200.00