(x + 10)² - 1
= (x² + 20x + 100) - 1
= x² + 20x + 99
None of the choices you provided are correct. Did you type in the question wrong?
Answer:
y = 20°
x = 35°
Explanation:
Equation's:
1) 2y + x + 105° = 180°
2) 3x + x + 2y = 180°
Make y subject in equation 2
3x + x + 2y = 180
4x + 2y = 180
2y = 180 - 4x
y = 90 - 2x
Insert this into equation 1
2(90 - 2x) + x + 105° = 180°
180 - 4x + x + 105 = 180
-3x = -105
x = 35°
Find value of y
y = 90 - 2x
y = 90 - 2(35)
y = 20°
Answer: The required fourth term of the geometric sequence is 
Step-by-step explanation: We are given to find the value of the fourth term in a geometric sequence with first term and common ratio as follows :

We know that
the n-th term of a geometric sequence with first term a1 and common ratio r given by

Therefore, the fourth term of the given geometric sequence will be
Thus, the required fourth term of the geometric sequence is 
Answer:
A, B, C, and D, all options are correct.
A is correct because,
∠2 and ∠3 are corresponding angles.
B is correct because,
∠5 and ∠7 are corresponding angles.
C is correct because,
∠2 and ∠4 are corresponding angles.
D is correct because,
∠5 and ∠6 are alternate interior angles.
Note,
If two lines parallel, then
- Corresponding angles are equal.
- Alternate interior angles are equal.