2x+13=3x-2 can be the equation (I believe)
The change that happened from the first half of the equation to the second half was you moved the 9 and the 4c around.
Commutative property of addition allows you to do that. It's what says that 2+3 is the same thing as 3+2
Answer:
la respuesta es 86
Step-by-step explanation:
a. Notice that
1/(1*2) = 1/2 = 1 - 1/2
1/(2*3) = 1/6 = 1/2 - 1/3
1/(3*4) = 1/12 = 1/3 - 1/4
and so on, which suggests the n-th term of the sum can be written as

Then the sum itself is telescoping:



b. The proof is trivial:

so the formula found in (a) is correct.