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бх + 7(1-x) = -4(x-4)

step-by-step explanation:

total income = price of one ticket   *   number of tickets sold

  y                 =     4                                   x

so the equation is y=4x     with x≥0   because number of tickets sold can not be negative

thus the equation is a semi -line with an end point at

(0,0)

passing through :

x=1     y=4(1) = 4   so through (1,4)