diketahui f(x) = 8 - 5x. jika f(a) = -12, maka nilai a adalah

[tex]f_{(x)} = 8-5x [/tex]
[tex]f_{(a)} = -12 \\ f_{(a)} = 8-5a \\ -12 = 8- 5a \\ 5a = 8 + 12 \\ 5a = 20 \\ a= 4 [/tex]

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