Step-by-step explanation:

The simplest method is "brute force". Calculate each term and add them up.
∑ = 3(1) + 3(2) + 3(3) + 3(4) + 3(5)
∑ = 3 + 6 + 9 + 12 + 15
∑ = 45

∑ = (2×1)² + (2×2)² + (2×3)² + (2×4)²
∑ = 4 + 16 + 36 + 64
∑ = 120

∑ = (2×3−10) + (2×4−10) + (2×5−10) + (2×6−10)
∑ = -4 + -2 + 0 + 2
∑ = -4
4. 1 + 1/4 + 1/16 + 1/64 + 1/256
This is a geometric sequence where the first term is 1 and the common ratio is 1/4. The nth term is:
a = 1 (1/4)ⁿ⁻¹
So the series is:

5. -5 + -1 + 3 + 7 + 11
This is an arithmetic sequence where the first term is -5 and the common difference is 4. The nth term is:
a = -5 + 4(n−1)
a = -5 + 4n − 4
a = 4n − 9
So the series is:

Answer:
Area of PSTK = 50
Step-by-step explanation:
△SPK:
SK = 13, PK = 12
13^2 - 12^2 = SP^2
SP = 5
(8 + 12) /2 x 5 = 50
Answer:
Area of the smaller square is x * x, which is x^2
Area of the larger square is (x + 7)(x + 7), which is x^2 + 14x + 49
The area of the shaded area = Area of the larger square - Area of the smaller square
Area of the shaded region = x^2 + 14x + 49 - x^2
Area of the shaded region is 14x + 49.
Given:
Last year Lira earned $12,000 less than her husband Todd.
Together they earned $75,000.
To find:
The amount earned by Lira in last year.
Solution:
Let x be the amount earned by Lira's husband inn last year.
Last year Lira earned $12,000 less than her husband Todd.
Amount earned by Lira = 
Total amount earned by Lira and her husband = 
= 
Together they earned $75,000.





Now,
Amount earned by Lira = 
= 
= 
Therefore, the amount earned by Lira in last year is $31500.
Answer:
The asnwer i fro 5/2 iss 2.5 and the other question is the answer is 1.3 is we add now is 3.8
Step-by-step explanation: