dik: a=81 b=-6
dit suku ke-n
Un : a + (n-1)b
: 81 + (n-1)-6
: 81 - 6n + 6
: - 6n + 87
[tex] \mathbb{ \color{aqua}{ \underbrace{JAWABAN}}}[/tex]
[tex] \boxed{ \bf{ \: 87 - 6n \: }}[/tex]
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[tex] \mathbb{ \color{orange}{ \underbrace{PENYELESAIAN}}}[/tex]
[tex] \boxed{ \begin{array}{c|c} \color{violet} \bf Rumus& \color{violet} \bf Keterangan \\ \hline & \tt{\color{magenta} U} \blue{_n} = suku \: ke - n ~~~~~~\\ \boxed{ \: \tt {\color{magenta} U} \color{aqua} \blue{_n} = \purple{a} + ( \blue{n} - 1) \orange{b} \: } & \tt \purple{a} = suku \: pertama~ \\ & \tt \orange{b} = beda \: (U_{2} - U_{1}) \end{array} } \\ \\ [/tex]
[tex] \boxed{\: \begin{aligned} \tt{a}& = \tt{ \purple{81}} \\ \tt{b}& = \tt{75 - 81} = \orange{ - 6} \end{aligned} \: } \\ \\ [/tex]
- rumus suku ke-n
[tex] \boxed{\: \begin{aligned} \tt{U_{n}}& = \tt{ \purple{a} + ( \blue{n} - 1) \orange{b}} \\ \tt{U_{n}}& = \tt{ \purple{81} + ( \blue{n} - 1)( \orange{ - 6})} \\ \tt{U_{n}}& = \tt{ \purple{81} + - 6n + 6} \\ \tt{U_{n}}& = \red{ \boxed{ \pink{ \bf{87 - 6n}}}} \end{aligned} \: }[/tex]
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[tex] \mathbb{ \color{red}{ \underbrace{KESIMPULAN}}}[/tex]
Jadi, rumus suku ke-n barisan tersebut adalah [tex] \pink{ \bf{87 - 6n}} [/tex]
[tex] \colorbox{ff0000}{} \colorbox{ff4000}{}\colorbox{ff8000}{}\colorbox{ffc000}{}\colorbox{ffff00}{}\colorbox{c0ff00}{}\colorbox{80ff00}{}\colorbox{40ff00}{}\colorbox{00ff00}{}\colorbox{00ff40}{}\colorbox{00ff80}{}\colorbox{00ffc0}{}\colorbox{00ffff}{}\colorbox{00c0ff}{}\colorbox{0080ff}{}\colorbox{0040ff}{}\colorbox{0000ff}{}\colorbox{4000ff}{}\colorbox{8000ff}{}\colorbox{c000ff}{}\colorbox{ff00ff}{}\colorbox{ff00c0}{}\colorbox{ff00a0}{}\colorbox{ff0080}{}\colorbox{ff0040}{} [/tex]
[answer.2.content]