Question

Please answer the ATTACHMENT mentioned above with proper steps. ​

Answer 1

Answer:

An even number

Step-by-step explanation:

If we take it as separate terms,

a= 3-9 = -6

$a_{2}$= 15-21 = -6, and so on.

This means that every term is -6, right up to the 19th term.

Since $x$ = 3-9 + 15-21 + ... up to 19 terms,

$x$ = (-6) + (-6) + ... up to 19 terms

$x$ = -6 x 19

$x$ = -114, which is an even number.

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