PLEASE EXPLAIN HOW U DID IT, giving brainliest

9514 1404 393
Answer:
(b) 30
Step-by-step explanation:
The standard form of a quadratic is ...
y = ax^2 +bx +c
For such a function, the axis of symmetry is ...
x = -b/(2a)
Your quadratic function has a=-5, b=+300, so the axis of symmetry is ...
x = -300/(2(-5) = 30
The peak of the curve is on the axis of symmetry. So, profit is maximized when 30 items are produced.
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Of course, a graphing calculator can display the maximum of the function easily.