Question

It's asking to solve for a1 but I don't really know how, please help.​

Answer 1

`C = (1)/(4)n( \: a(1) \: + \: a(2) \: ) \\`

Multiply sides by 4

`4 * C = 4 * (1)/(4)n( \: a(1) + a(2) \: ) \\`

`4C = n( \: a(1) + a(2) \: )`

Divided sides by n

`(4C)/(n) = (n)/(n)( \: a(1) + a(2) \: ) \\`

`(4C)/(n) = a(1) + a(2) \\`

Subtract sides - a (2)

`(4C)/(n) - a(2) = a(1) + a(2) - a(2) \\`

`(4C)/(n) - a(2) = a(1) \\`

`a(1) = (4C)/(n) - a(2) \\`

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Done ♥️♥️♥️♥️♥️