public void FirstSymbolEqualToSolveSymbolTest()
{
mathExpression = MathExpression.CreateExpression();
var subSymbol = Condition.TakeFirstSymbolEqualToSolveSymbol(mathExpression, SimpleCalculator.Enums.Operations.SubAndAdd);
var multSymol = Condition.TakeFirstSymbolEqualToSolveSymbol(mathExpression, SimpleCalculator.Enums.Operations.MulAndDiv);
Assert.AreEqual(subSymbol, mathExpression[1]);
Assert.AreEqual(multSymol, mathExpression[3]);
}