Question: Warning, solutions may have been lost, HELP!

Hello. I don't have much experience using Maple. Sorry if this question is really specific. I am trying to solve a system of six equations, with six variables. This is what i type into maple:

solve({0 = a_2*cos(7.5*b_2) + a_2, 250 = Pi*int((a_2*cos(b_2*x) + a_2)^2, x = 0 .. 7.5), 750 = Pi*int((a_1*x^2 + b_1*x + sqrt(d_1*x) + 7.5)^2 - (a_2*cos(b_2*x) + a_2)^2, x = 0 .. x_2), 2.5 = a_1*20^2 + 20*b_1 + sqrt(20*d_1) + 7.5, 2*a_1*x_2 + b_1 + sqrt(d_1)/(2*sqrt(x_2)) = 0, (2*a_1)*20 + b_1 + sqrt(d_1)/(2*sqrt(20)) = 0, x_2 <> 20}, {a_1, a_2, b_1, b_2, d_1, x_2})

When i try to solve i get the output "Warning, solutions may have been lost." When i try to remove the equeation that says that x_2 can't be equal to 20, i get some answers, but i want to know if there are any where x_2 is not 20. (I know that it also can be one other number, because of the type of function). Does the output i get mean that there simply aren't any answers where thos conditions are true, or that there might be some, that Maple can't figure out? If so, what could i do to figure it out? 

Thank you!