c_1, x_1, x_2, x_3, x_5, x_6, x_7, 
x_3
x_5
-c_1*(-2*x_1-x_2+40*c_1)
60*c_1^2+2*x_1*x_6+x_2*x_6
-48*c_1^5*x_1+16*c_1^5*x_2+2*x_1*x_7+x_2*x_7
