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What is r i 4.5+10r=-6.5 with work pls

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.

For the feasibility region shown below find the maximum value of the function p=3x+2y