Hey

I'm stuck on this word problem

Marginal revenue in thousands of dollars is: R'(x) = -0.6x + 7

where x is the number of units sold, in hundreds. Find the revenue if 350 units are sold, assume R(0) = 0

Okay so I did the anti derivative of the equation

with C equalling 0

(-0.6x^2)/2 + 7x/1 = Y

then substituted 350 into the equation

My answer was -34300, my text says the answer is 20825

Where have I gone wrong?????????

thanks in advance.