Respuesta :

Answer:

Thus: a7=-1

Step-by-step explanation:

Arithmetic Sequences

The arithmetic sequences are identified because each term is obtained by adding or subtracting a fixed number to the previous term.

The equation to calculate the nth term of an arithmetic sequence is:

[tex]a_n=a_1+(n-1)r[/tex]

We know: a12=29, a16=53, thus

[tex]a_1+(12-1)r=29[/tex]

[tex]a_1+(16-1)r=53[/tex]

Simplifying:

[tex]a_1+11r=29[/tex]

[tex]a_1+15r=53[/tex]

Subtracting both equations:

[tex]4r=53-29=24[/tex]

Solving:

[tex]r=24/4[/tex]

r=6

The 7th term can be found as 5 terms before the 12nd:

[tex]a_7=a_{12}-5r[/tex]

[tex]a_7=29-5*6=29-30=-1[/tex]

Thus: a7=-1