Answer:
B) 81°
Step-by-step explanation:
Given:
From the figure given below,
∠1 = 3x + 18
∠7 = 2x + 39
∠1 and ∠7 are a pair of exterior alternate angles. For two parallel lines l and m, cut by a transversal n, the pair of exterior alternate angles are congruent to each other.
Therefore, the angles 1 and 7 are congruent to each other. This gives,
∠1 ≅ ∠7
Therefore, the value of 'x' is 21.
Now, the measure of angle 7 can be calculated by plugging in the value of 'x' in the expression for angle 7. This gives,
Therefore, the correct option is option (B).
Answer:
<h3>The option A)Step-by-step explanation:
Given expression is x to the 12th power times z to the 11th power all over x to the 2nd power times z to the 4th power.
The given expression can be written as
Now we have to simplify the given expression as below
( by using the identity
)
( by using the identity
)
∴
Given:
First term of an arithmetic sequence is 2.
Sum of first 15 terms = 292.5
To find:
The common difference.
Solution:
We have,
First term:
Sum of first 15 terms:
The formula of sum of first n terms of an AP is
Where, a is first term and d is common difference.
Putting , n=15 and a=2 in the above formula, we get
Divide both sides by 15.
Dividing both sides by 7, we get
Therefore, the common difference is 2.5.