Area of the rectangle is L x w = 20 * 15 = 300
Area of the triangle = 1/2 x base x height = 1/2 x 15 x 12 = 90
Total area = 300 + 90 = 390 cm^2
Divide the top and bottom by the highest number that can divide into BOTH numbers.
Answer:
![a_n=6n-13](https://tex.z-dn.net/?f=a_n%3D6n-13)
Step-by-step explanation:
<u>Arithmetic Sequences</u>
The arithmetic sequences can be identified because each term is obtained by adding or subtracting a fixed number to the previous term. That number is called the common difference.
The equation to calculate the nth term of an arithmetic sequence is:
![a_n=a_1+(n-1)r](https://tex.z-dn.net/?f=a_n%3Da_1%2B%28n-1%29r)
Here a1 is the first term and r is the common difference.
The given sequence is:
![a_1=-7, a_2=-1,a_3=5,a_4=11,...](https://tex.z-dn.net/?f=a_1%3D-7%2C%20a_2%3D-1%2Ca_3%3D5%2Ca_4%3D11%2C...)
We can find the common difference by subtracting successive terms:
![a_2-a_1=-1+7=6](https://tex.z-dn.net/?f=a_2-a_1%3D-1%2B7%3D6)
![a_3-a_2=5+1=6](https://tex.z-dn.net/?f=a_3-a_2%3D5%2B1%3D6)
![a_4-a_3=11-5=6](https://tex.z-dn.net/?f=a_4-a_3%3D11-5%3D6)
Since all the differences are equal, r=6. Thus, the general term is:
![a_n=-7+6(n-1)](https://tex.z-dn.net/?f=a_n%3D-7%2B6%28n-1%29)
Operating:
![a_n=-7+6n-6](https://tex.z-dn.net/?f=a_n%3D-7%2B6n-6)
![a_n=6n-13](https://tex.z-dn.net/?f=a_n%3D6n-13)
The nth term is:
![\mathbf{a_n=6n-13}](https://tex.z-dn.net/?f=%5Cmathbf%7Ba_n%3D6n-13%7D)