Answer:
(y - 25) = - 0.25(x - 20)
Step-by-step explanation:
Given that :
Height of candle after burning for 20 minutes = 25 cm
Height after burning for 1 hr (60 minutes) = 10 cm
Height (y) in cm of candle x minutes after being lit:
Using the equation :
(y - y1) = m(x - x1)
m = (change in y / change in x)
Change in height within 60 minutes :
Height at 20 minutes = 25cm
Height after an hour = 10
Change in height per hour = (25 - 10) = 15cm
Hence, m = change in height per minute
15cm / 60 = 0.25cm ( - 0.25) (decrease in height)
y1 = 25 ; x1 = 20
(y - y1) = m(x - x1)
(y - 25) = - 0.25(x - 20)
Answer:
<u>The correct answer is B. x ≈ 4.5, y = 5, z = 9</u>
Step-by-step explanation:
1. We will use the Pythagorean theorem for solving for x, this way:
x² = 6² - 4²
x² = 36 - 16
x² = 20
x = √20
x = 2 √5 = 4.47 ≈ 4.5
2. For solving for y, we will do it this way:
There are only two possible options: y = 5, included in answer B or y = 9 as it is defined on answer C.
If we review it carefully, we will realize that y = 9 is not accurate because as we can see in the graph y + 4 = z and in this specific case, 9 + 4 ≠ 5 but it's true that 5 + 4 = 9.
<u>Because of this reason, the correct answer is B. x ≈ 4.5, y = 5, z = 9</u>
We have the equation:
By arranging this equation in terms of x and y, we have:
By using the method of completing the square, we have:
The center of this circle is:
So the equation that fulfills the statement is:
Finally, the right answer is c)
Answer:
-6
Step-by-step explanation:
We know that since Ax + By = 3 passes through (-7, 2), then if we plug -7 in for x and 2 in for y, the equation is satisfied. So, let's do that:
Ax + By = 3
A * (-7) + B * 2 = 3
-7A + 2B = 3
We also know that this line is parallel to x + 3y = -5, which means their slopes are the same. Let's solve for y in the second equation:
x + 3y = -5
3y = -x - 5
y = (-1/3)x - (5/3)
So, the slope of this line is -1/3, which means the slope of Ax + By = 3 is also -1/3. Let's solve for y in the first equation:
Ax + By = 3
By = -Ax + 3
y = (-A/B)x + 3/B
This means that -A/B = -1/3. So, we have a relationship between A and B:
-A/B = -1/3
A/B = 1/3
B = 3A
Plug 3A in for B into the equation we had where -7A + 2B = 3:
-7A + 2B = 3
-7A + 2 * 3A = 3
-7A + 6A = 3
-A = 3
A = -3
Use this to solve for B:
B = 3A
B = 3 * (-3) = -9
So, B = -9 and A = -3. Then B - A is:
B - A = -9 - (-3) = -9 + 3 = -6
The answer is -6.
<em>~ an aesthetics lover</em>
