Có nên dùng con trỏ this?

e viết thư viện như sau?
có cần thiết dùng con trỏ this ạ?

#include <iomanip>
#include <complex>
#include <iostream>
using namespace std;

#define MAX 10

class MaTran
{
	public:
		MaTran(int m, int n);
		~MaTran();
		void inMaTran();
		void nhapMaTran();
		void chuyenVi();
		int dinhThuc(int p=0);
		float phuHop(int hangXoa, int cotXoa);
		void nghichDao();
		int hang();
		void xoaHang();
		void xoaCot();
		void congMaTran();
		void truMaTran();
		void nhanMT_So();
		void nhanMT_MT();
	private:
		int soHang=MAX,soCot=MAX;
		float det=0;
		float **mt=new float*[soHang];
};

MaTran::MaTran(int m, int n){
	this->soHang=m;
	this->soCot=n;
	for(int i=0;i<this->soHang;i++)
		this->mt[i]=new float[this->soCot];
}

MaTran::~MaTran(){
	for(int i=0;i<this->soHang;i++) delete[] this->mt[i];
	delete[] this->mt;
	this->soHang=0; this->soCot=0;
	this->det=0;
}

void MaTran::inMaTran(){
	cout<<fixed<<setprecision(2);
	for(int i=0;i<this->soHang;i++){
		cout<<"
	";
		for(int j=0;j<this->soCot;j++) cout<<setw(4)<<this->mt[i][j]<<" ";
	}
	cout<<endl;
}

void MaTran::nhapMaTran(){
	for(int i=0;i<this->soHang;i++)
		for(int j=0;j<this->soCot;j++){
			cout<<"	Phan tu ["<<i+1<<","<<j+1<<"] = ";
			cin>>this->mt[i][j];
		}
	cout<<"Ma tran ban vua nhap la:";
	this->inMaTran();
}

void MaTran::chuyenVi(){
	MaTran cv(this->soCot,this->soHang);
	for(int i=0;i<cv.soHang;i++)
		for(int j=0;j<cv.soCot;j++)
			cv.mt[i][j]=this->mt[j][i];
	cout<<"Ma tran chuyen vi cua ma tran A la:";
	cv.inMaTran();
}

int MaTran::dinhThuc(int p){
	if(this->soHang==this->soCot){
		int i=0,d=0;
		float dt=1.0;
		//Tao ma tran B lay gia tri cua ma tran A
		MaTran b(this->soHang,this->soCot);
		for(int i=0;i<b.soHang;i++)
			for(int j=0;j<b.soCot;j++)
				b.mt[i][j]=this->mt[j][i];
		//Dua ma tran ve ma tran tam giac tren
		for(i=0;i<b.soHang-1;i++){
			if(b.mt[i][i]==0)
				for(int k=i+1;k<b.soHang;k++){
					bool c=0;
					if(b.mt[k][i]!=0){
						for(int j=0;j<b.soCot;j++){
							float t=b.mt[i][j];
							b.mt[i][j]=b.mt[k][j];
							b.mt[k][j]=t;
						}
						d++;
						c=1;
						break;
					}
					if(c) break;
				}
			for(int k=i+1;k<b.soHang;k++){
				double tl=b.mt[k][i]/b.mt[i][i];
				for(int j=0;j<soCot;j++)
					b.mt[k][j]-=b.mt[i][j]*tl;
			}
		}
		//Tinh dinh thuc bang tich cac phan tu tren duong cheo chinh
		for(i=0;i<b.soCot;i++) dt*=b.mt[i][i];
		if(dt!=0) dt*=pow(-1,d);
		this->det=dt;
		if(p) cout<<"	Dinh thuc cua ma tran A la: det(A) = "<<this->det<<endl;
		return 0;
	} else{
		return 1;
	}
}

float MaTran::phuHop(int hangXoa, int cotXoa){
	MaTran ph(this->soHang-1,this->soCot-1);
	for(int i=0;i<hangXoa;i++){
		for(int j=0;j<cotXoa;j++)
			ph.mt[i][j]=this->mt[i][j];
		for(int j=cotXoa;j<ph.soCot;j++)
			ph.mt[i][j]=this->mt[i][j+1];
	}
	for(int i=hangXoa;i<ph.soHang;i++){
		for(int j=0;j<cotXoa;j++)
			ph.mt[i][j]=this->mt[i+1][j];
		for(int j=cotXoa;j<ph.soCot;j++)
			ph.mt[i][j]=this->mt[i+1][j+1];
	}
	ph.dinhThuc(0);
	float pTu=(float) ph.det/this->det;
	if(pTu!=0)
		pTu*=pow(-1,hangXoa+cotXoa);
	return pTu;
}

void MaTran::nghichDao(){
	if(this->dinhThuc(0)==1 || this->det==0) cout<<"	Ma Tran A khong kha nghich
";
	else{
		//Tao ma tran chuyen vi cua ma tran A
		MaTran cv(this->soCot,this->soHang);
		for(int i=0;i<cv.soHang;i++)
			for(int j=0;j<cv.soCot;j++)
				cv.mt[i][j]=this->mt[j][i];
		//Tao ma tran B co cac phan tu la ma tran phu hop cua ma tran chuyen vi
		MaTran b(this->soHang,this->soCot);
		cv.det=this->det;
		for(int i=0;i<b.soHang;i++)
			for(int j=0;j<b.soCot;j++)
				b.mt[i][j]=cv.phuHop(i,j);
		cout<<"Ma tran nghich dao cua ma tran A la:";
		b.inMaTran();
	}
}

int MaTran::hang(){
	//Tao ma tran B lay gia tri cua ma tran A
	MaTran b(this->soHang,this->soCot);
	for(int i=0;i<b.soHang;i++)
		for(int j=0;j<b.soCot;j++)
			b.mt[i][j]=this->mt[i][j];
	//Dua ma tran ve ma tran tam giac tren
	for(int i=0;i<b.soHang-1;i++){
		for(int j=i;j<b.soCot;j++){
			if(b.mt[i][j]==0)
				for(int k=i+1;k<b.soHang;k++)
					if(b.mt[k][j]!=0){
						for(int u=0;u<b.soCot;u++){
							float t=b.mt[i][u];
							b.mt[i][u]=b.mt[k][u];
							b.mt[k][u]=t;
						}
						break;
					}
			if(b.mt[i][j]!=0){
				for(int k=i+1;k<b.soHang;k++){
					double tl=(double) b.mt[k][j]/b.mt[i][j];
					for(int u=0;u<b.soCot;u++){
						b.mt[k][u]-=b.mt[i][u]*tl;
					}
				}
				break;
			}
		}
	}
	//Tim hang
	int r=0;
	for(int i=b.soHang-1;i>=0;i--){
		for(int j=0;j<b.soCot;j++)
			if(abs(b.mt[i][j])!=0){
				r=i+1;
				break;
			}
		if(r>0) break;
	}
	return r;
}

void MaTran::xoaHang(){
	int x=0;
	do{
		cout<<"Nhap vao hang thu x (0<x<"<<this->soHang+1<<") ban muon xoa: ";
		cin>>x;
	} while(x<1 || x>this->soHang);
	MaTran b(this->soHang-1,this->soCot);
	x--;
	for(int j=0;j<b.soCot;j++){
		for(int i=0;i<x;i++)
			b.mt[i][j]=this->mt[i][j];
		for(int i=x;i<b.soHang;i++)
			b.mt[i][j]=this->mt[i+1][j];
	}
	cout<<"Ma tran A sau khi xoa hang thu "<<x+1<<" la:";
	b.inMaTran();
}

void MaTran::xoaCot(){
	int x=0;
	do{
		cout<<"Nhap vao cot thu x (0<x<"<<this->soCot+1<<") ban muon xoa: ";
		cin>>x;
	} while(x<1 || x>this->soCot);
	MaTran b(this->soHang,this->soCot-1);
	x--;
	for(int i=0;i<b.soHang;i++){
		for(int j=0;j<x;j++)
			b.mt[i][j]=this->mt[i][j];
		for(int j=x;j<b.soCot;j++)
			b.mt[i][j]=this->mt[i][j+1];
	}
	cout<<"Ma tran A sau khi xoa cot thu "<<x+1<<" la:";
	b.inMaTran();
}

void MaTran::congMaTran(){
	MaTran b(this->soHang,this->soCot);
	cout<<"Nhap ma tran B:
";
	b.nhapMaTran();
	for(int i=0;i<b.soHang;i++)
		for(int j=0;j<b.soCot;j++){
			b.mt[i][j]+=this->mt[i][j];
		}
	cout<<"Tong cua 2 ma tran A va B la:";
	b.inMaTran();
}

void MaTran::truMaTran(){
	MaTran b(this->soHang,this->soCot);
	cout<<"Nhap ma tran B:
";
	b.nhapMaTran();
	for(int i=0;i<b.soHang;i++)
		for(int j=0;j<b.soCot;j++){
			b.mt[i][j]=this->mt[i][j]-b.mt[i][j];
		}
	cout<<"Hieu cua 2 ma tran A va B la:";
	b.inMaTran();
}

void MaTran::nhanMT_So(){
	float x=1;
	MaTran b(this->soHang,this->soCot);
	cout<<"Nhap vao so x: ";
	cin>>x;
	for(int i=0;i<b.soHang;i++)
		for(int j=0;j<b.soCot;j++)
			b.mt[i][j]=x*this->mt[i][j];
	cout<<"Tich cua "<<x<<" voi ma tran A la:";
	b.inMaTran();
}

void MaTran::nhanMT_MT(){
	int cotB=10;
	cout<<"Nhap so cot cua ma tran B: ";
	cin>>cotB;
	MaTran b(this->soCot,cotB);
	cout<<"
Nhap ma tran B:
";
	b.nhapMaTran();
	MaTran c(this->soHang,b.soCot);
	for(int i=0;i<c.soHang;i++)
		for(int j=0;j<c.soCot;j++){
			c.mt[i][j]=0;
			for(int k=0;k<this->soCot;k++)
				c.mt[i][j]+=this->mt[i][k]*b.mt[k][j];
		}
	cout<<"Tich cua ma tran A va ma tran B la:";
	c.inMaTran();
}