如何在mathview（android studio）中生成setter和getter？

public void makeCalculations() {

        double n1 = Double.valueOf(V2.getText().toString());
        double n2 = Double.valueOf(V1.getText().toString());
        double n3 = Double.valueOf(R2.getText().toString());
        double n4 = Double.valueOf(R1.getText().toString());
        double n5 = Double.valueOf(Rf.getText().toString());
        double n6 = Double.valueOf(Rg.getText().toString());
        double n7 = Double.valueOf(va.getText().toString());
        double n8 = Double.valueOf(vb.getText().toString());
        double n9 = Double.valueOf(vout.getText().toString());
        double I1 = (n2-n7)/n4 ;
        double I2 = (n1-n8)/n3;
        double If = (n7-n9)/n5;

在这里，当我在“$$”后面添加setter和getter时，它会标记一个错误

courant = (MathView) findViewById(R.id.courant);
        Resumé.setText("  $$I1 = \\frac{Va - Vb}{R1}$$ " + "=\n" + "  $$I1 = \\frac{n2 - n7}{n4}$$ " +"="+ I1+"\n"
      + "  $$I2 = \\frac{Vb - V2}{R2}$$ "+ "=\n" + "  $$I2 = \\frac{n8 - n1}{n3}$$ " +"="+ I2+"\n"
 +"  $$If =\\frac{Va - Vout}{R3}$$ "+"=\n" + "  $$If = \\frac{n2 - n9}{n5}$$ " +"="+ If +"\n");