Write the Expression for the General (Or Nth)term, An, of the Arithmetic

question 7

Multiple Choice

Write the expression for the general (or nth) term, an, of the arithmetic sequence. Then, find the indicated term of the
arithmetic sequence.
- $a = - 10 , d = 3 ; \quad \text { find } a _ { n } \text { and } a _ { 7 }$

• A) \(a _ { n } = - 13 - 3 n , a _ { 7 } = 8\)
• B) \(a _ { n } = - 13 + 3 n , a _ { 7 } = 8\)
• C) \(a _ { n } = - 10 + 3 n , a _ { 7 } = 8\)
• D) \(a _ { n } = - 13 + 3 n , a _ { 7 } = 32\)

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Definitions:

MgO Content

The percentage of Magnesium Oxide present in a geological sample, important in determining rock composition and origins.

SiO Content

Refers to the concentration of Silicon Dioxide, a common compound found in the Earth's crust, often significant in determining the composition of rocks and soils.

Mafic Minerals

Dark-colored minerals that are rich in magnesium and iron, typically found in basalt and other mafic rocks.

Quartz

A hard, crystalline mineral composed of silicon and oxygen atoms, used in making jewelry, electronics, and optical devices.