![a_n=48+3(2n-1)](https://tex.z-dn.net/?f=a_n%3D48%2B3%282n-1%29)
The formula of the sum of the arithmetic sequence:
![S_n=\dfrac{a_1+a__n}{2}\cdot n](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Ba_1%2Ba__n%7D%7B2%7D%5Ccdot%20n)
calculate:
![a_1=48+3(2\cdot1-1)=48+3=51](https://tex.z-dn.net/?f=a_1%3D48%2B3%282%5Ccdot1-1%29%3D48%2B3%3D51)
substitute
![S_n=\dfrac{51+48+3(2n-1)}{2}\cdot n=\dfrac{99+6n-3}{2}\cdot n=\dfrac{96+6n}{2}\cdot n=3n^2+48n](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7B51%2B48%2B3%282n-1%29%7D%7B2%7D%5Ccdot%20n%3D%5Cdfrac%7B99%2B6n-3%7D%7B2%7D%5Ccdot%20n%3D%5Cdfrac%7B96%2B6n%7D%7B2%7D%5Ccdot%20n%3D3n%5E2%2B48n)
Your answer is:
Answer:
In total Dan dranked 11/8 of his bottle or as a mixed number 1 and 3/8 of his bottle.
Step-by-step explanation:
3(x-1) = 2x - y
3x-3 = 2x-y
3x-2x+y = 3
x + y = 3 ----> (1)
2(x+y) = 3+3y
2x + 2y = 3 + 3y
2x + 2y - 3y = 3
2x - y = 3 -----> (2)
make equation (1) and (2) together
x + y + 2x - y = 3+3
3x = 6
x = 2
now make x = 2 in equation (1)
x + y = 3
2 + y = 3
y = 3-2
y = 1
(x,y) = (2,1)
Answer:
1) f(3) means the temperature after 3 seconds
2) f(3) = 22 + 1.3(3) = 25.9
Temperature after 3 seconds is 25.9°C
3) f(t) = 35 means after t seconds, temperature was 35°C
4) 35 = 22 + 1.3t
1.3t = 13
t = 10 seconds
The given system of equations represent a single line with positive slope. So option C is correct.
<u>SOLUTION:
</u>
Given system of equations are
![\begin{array}{l}{3 y-5 x=15 \rightarrow(1)} \\\\ {6 y-10 x=30 \rightarrow(2)}\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bl%7D%7B3%20y-5%20x%3D15%20%5Crightarrow%281%29%7D%20%5C%5C%5C%5C%20%7B6%20y-10%20x%3D30%20%5Crightarrow%282%29%7D%5Cend%7Barray%7D)
Now, if we observe,
multiplying the
equation with 2 results in
equation.
which means the two line equations represents the same line.
Now, let us find the slope of line, ![\text { slope }=\frac{-x \text { coefficient }}{y \text { coefficient }}=\frac{-3}{-5}=\frac{3}{5}=\text { positive slope }](https://tex.z-dn.net/?f=%5Ctext%20%7B%20slope%20%7D%3D%5Cfrac%7B-x%20%5Ctext%20%7B%20coefficient%20%7D%7D%7By%20%5Ctext%20%7B%20coefficient%20%7D%7D%3D%5Cfrac%7B-3%7D%7B-5%7D%3D%5Cfrac%7B3%7D%7B5%7D%3D%5Ctext%20%7B%20positive%20slope%20%7D)
So, the line has a positive slope.