This is a simultaneous question.
To solve this, we have to make up 2 equations based on the info provided like so:
electricity = e
gas = g
600e + 100g = $412 ——(1)
400e + 150g = $293 ——(2)
In this case, it’ll be easier to use the elimination method where you eliminate a variable so you can calculate only one.
Here, we will be eliminating e so we can get the cost of gas.
To do this we need to get both equation’s e to 600, so we have to multiply equation 2 by 1.5:
(2) x 1.5:
400e + 150g = $293
600e + 225g = $439.50 ——(3)
Now we eliminate e by subtracting equation 1 from equation 3:
(3) - (1):
600e + 225g - 600e - 100g = $439.50 -$412
125g = $27.50
g = $0.22.
Therefore one unit of gas costs $0.22.
Hope it helps and have a good day ahead :D
Cosine is a trigonometric function. The value of cos(x+π), when the value of cos(x)=-(√3)/2 is √3/2. The correct option is A.
<h3>What is a cosine?</h3>
Cosine is the trigonometric function equal to the ratio of the side next to an acute angle to the hypotenuse in a right-angled triangle.
Given the value of cos(x)=-(√3)/2, therefore, the value of x can be written as,
cos(x) = -(√3)/2
(x) = cos⁻¹ [-(√3)/2]
x = 5π/6 = 150°
Now, the value of cos(x+π) will be,
cos(x+π)
= cos[(5π/6)+π]
= cos(11π/6)
= √3 / 2
Hence, the value of cos(x+π), when the value of cos(x)=-(√3)/2 is √3/2.
Learn more about Cosine function here:
brainly.com/question/17954123
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Integers are 2n and 2n +2
2n * (2n + 2) = 840
4n^2 + 4n -840 = 0
Solving by quadratic formula:
n = 14 and n+2 = 16
Therefore the integers (2*n and 2*n+2) are
28 and 30
check:
28 * 30 = 840
