=> MathS.Equations(eqs.eq1, eqs.eq2, eqs.eq3, eqs.eq4, eqs.eq5, eqs.eq6, eqs.eq7, eqs.eq8, eqs.eq9).Solve(var1, var2, var3, var4, var5, var6, var7, var8, var9);
 => MathS.Equations(eqs.eq1, eqs.eq2, eqs.eq3, eqs.eq4, eqs.eq5).Solve(var1, var2, var3, var4, var5);
 => MathS.Equations(eqs.eq1, eqs.eq2, eqs.eq3, eqs.eq4, eqs.eq5, eqs.eq6, eqs.eq7).Solve(var1, var2, var3, var4, var5, var6, var7);
 => MathS.Equations(eqs.eq1, eqs.eq2, eqs.eq3, eqs.eq4).Solve(var1, var2, var3, var4);