csat-suneung 2009 Q20

csat-suneung · South-Korea · csat__math-humanities 3 marks Arithmetic Sequences and Series Find Specific Term from Given Conditions
For an arithmetic sequence $\left\{ a _ { n } \right\}$ with common difference 2,
$$a _ { 1 } + a _ { 5 } + a _ { 9 } = 45$$
Find the value of $a _ { 1 } + a _ { 10 }$. [3 points]
For an arithmetic sequence $\left\{ a _ { n } \right\}$ with common difference 2,

$$a _ { 1 } + a _ { 5 } + a _ { 9 } = 45$$

Find the value of $a _ { 1 } + a _ { 10 }$. [3 points]