Answer:
The answer is x=12.
Step-by-step explanation:
First, to solve this equation you need to isolate the x variable. To isolate the variable, you must, subtract the other term from both sides. Subtracting 18 from both sides, you are left with 3x = 36. Since 3 times x = 36, dividing both sides by 3 gets you, x=12.
The series 7 + 16 + 25 +34 +43 +52 + 61 is an illusration of arithmetic series
The sigma notation of the series is: 
<h3>How to write the series in sigma notation?</h3>
The series is given as:
7 + 16 + 25 +34 +43 +52 + 61
The above series is an arithmetic series, with the following parameters
- First term, a = 7
- Common difference, d = 9
- Number of terms, n = 7
Start by calculating the nth term using:
a(n) = a + (n - 1) * d
This gives
a(n) = 7 + (n - 1) * 9
Evaluate the product
a(n) = 7 - 9 + 9n
Evaluate the difference
a(n) = 9n - 2
So, the sigma notation is:

Read more about arithmetic series at:
brainly.com/question/6561461
180 - 53 - 96 = 31°. you know the angles are 53 and 96 degrees because the triangles are congruent via SAS congruency.
1)16^2 or 4^4
2)3^2
3)4^2
4)5^2
5)15^2
6)14^2