def display(self,disp):
        dis = ''
        c=0
        for i in disp:
            if(c==0):
                dis = dis + str(i[0])+'*x^'+str(i[1])
                c = c+1
            else:
                dis = dis+'+'+str(i[0])+'*x^'+str(i[1])
        dis = dis.replace('+-','-')
        return dis