+local function solve_1(coef)
+ local a, b, c = coef[1][4], coef[2][4], coef[3][4]
+ coef[1][4], coef[2][4], coef[3][4] = c-b, a+b-c, c-a
+ return coef
+end
+
+local function solve_2(coef)
+ local a, b, c, d, e = coef[1][6], coef[2][6], coef[3][6], coef[4][6], coef[5][6]
+ coef[1][6], coef[2][6], coef[3][6], coef[4][6], coef[5][6]
+ = e-c, a+c-e, e-a-d, b+d-e, e-b
+ return coef
+end
+
+