Answer:
-<u>One Equation</u>: is set equal to a variable
Example:
y = 2x + 1
x + 3y = -12
You already have y, plug it back into x + 3y = -12
x + 3(2x + 1) = -12
x + 6x + 3 = -12
7x + 3 = -12
(Subtract 3 from each side)
7x = -15
(Divide by 7)
x = - 2.14
-<u>No Equation</u>: is set equal to a variable
Example:
2x + y = 10
4× + 2y = -3
Subtract 2x from each side of 2x + y = 10, you should get y= -2x + 10. Now that you have found y, substitute y into 4x+ 2y = -3.
4x + 2(-2x + 10) = -3
4x + -4x + 20 = -3
(Subtract 20 from each side)
4x + -4x = -23
(Add 4x and -4x)
0 = -23
No Solution
<u>-Both</u><u> </u><u>Equations</u>: are set equal to a variable
Example:
y = x + 5
y = -x + 3
(you already have y so plug it into the other equation to solve for x)
-x + 3 = x + 5
(Add -x on both sides)
3 = 2x + 5
(subtract 5 from both sides)
-2 = 2x
(Divide by 2 on each side)
x = -1
I hope this helped!
Answer: 0.004 (you can ask Siri this question and get the same answer)
Answer:
it's B I think because I worked it out and I got B
The percentage of the semicircle shaded section is approximately 23,606 %.
The percentage of the area of the semicircle is equal to the ratio of the semicircle area minus the half-cross area to the semicircle area. In other words, we have the following expression:
(1)
Where:
- Area of the half cross, in square centimeters.
- Area of the semicircle, in square centimeters.
- Percentage of the shaded section of the semicircle.
And the percentage of the shaded section is:
![r = \left[1-\frac{4 \cdot (2\,cm)^{2}+4\cdot \left(\frac{1}{2} \right)\cdot (2\,cm)^{2}}{0.5\cdot \pi\cdot (16\,cm^{2}+4\,cm^{2})} \right]\times 100](https://tex.z-dn.net/?f=r%20%3D%20%5Cleft%5B1-%5Cfrac%7B4%20%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%2B4%5Ccdot%20%5Cleft%28%5Cfrac%7B1%7D%7B2%7D%20%5Cright%29%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%7D%7B0.5%5Ccdot%20%5Cpi%5Ccdot%20%2816%5C%2Ccm%5E%7B2%7D%2B4%5C%2Ccm%5E%7B2%7D%29%7D%20%5Cright%5D%5Ctimes%20100)
The percentage of the semicircle shaded section is approximately 23,606 %.
We kindly invite to check this question on percentages: brainly.com/question/15469506
680 is the answer to that question
