Question 624530
A(x) = (b*h)/2


A(x) = ((6x)(9x-1))/2


A(x) = (54x^2-6x)/2


A(x) = (2(27x^2-3x))/2


A(x) = 27x^2-3x


From here, plug in x = 50 into the last equation above and evaluate to find A(50).