Answer:
53
Step-by-step explanation:
5+3=8, 53 flipped is 35, and 53-35=18
These calculations are based on the drawing of the file enclosed.
There are three right triangles.
From the big right triangle:
a^2 + b^2 = 25^2
From the small right triangle on the left side:
(25-x)^2 + 10^2 = a^2
From the small right triangle on the right side
x^2 +10^2 = b^2
=> (25-x)^2 + 10^2 + x^2 + 10^2 = a^2 + b^2
=> (25-x)^2 + 10^2 + x^2 + 10^2 = 25^2
=> 25^2 - 50x + x^2 + 10^2 + 10^2 = 25^2
=> x^2 -50x + 100 =0
Use the quadratic formular to find the roots:
x = 2.1 and x = 47.9
Distance from back: 25 - 2.1 = 22.9 ft
Answer: 22.9 ft
Let S be the sum,
S = 2 + 4 + 6 + ... + 2 (n - 2) + 2 (n - 1) + 2n
Reverse the order of terms:
S = 2n + 2 (n - 1) + 2 (n - 2) + ... + 6 + 4 + 2
Add up terms in the same positions, so that twice the sum is
2S = (2n + 2) + (2n + 2) + (2n + 2) + ... + (2n + 2)
or
2S = n (2n + 2)
Divide both sides by 2 to solve for S :
S = n (n + 1)
