class Vector2 {
	constructor(x, y) {
  	this.x = x;
    this.y = y;
  }
  
  timesMatrix2(matrix2) {
    const newX = (this.x * matrix2.m00) + (this.y * matrix2.m10);
    const newY = (this.x * matrix2.m01) + (this.y * matrix2.m11);
    
    return new Vector2(newX, newY);
  }
  
  magnitude() {
    return Math.sqrt(this.x ** 2 + this.y ** 2);
  }
}

class Matrix2 {
  constructor(m00, m01, m10, m11) {
    this.m00 = m00; this.m01 = m01;
    this.m10 = m10; this.m11 = m11;
  }
  
  timesMatrix2(otherMatrix2) {
    const newM00 = (this.m00 * otherMatrix2.m00) + (this.m01 * otherMatrix2.m10);
    const newM01 = (this.m00 * otherMatrix2.m01) + (this.m01 * otherMatrix2.m11);
    const newM10 = (this.m10 * otherMatrix2.m00) + (this.m11 * otherMatrix2.m10);
    const newM11 = (this.m10 * otherMatrix2.m01) + (this.m11 * otherMatrix2.m11);
    
    return new Matrix2(newM00, newM01, newM10, newM11);
  }
}

const vector = new Vector2(5, 6);
const firstMatrix = new Matrix2(5, 6, 7, 8);
const secondMatrix = new Matrix2(1, 2, 3, 4);

const vectorResult = vector.timesMatrix2(secondMatrix);

// Logs 23 34
console.log(vectorResult.x, vectorResult.y);

const matrixResult = firstMatrix.timesMatrix2(secondMatrix);

// Logs 23 34 31 46
console.log(matrixResult.m00, matrixResult.m01, matrixResult.m10, matrixResult.m11);

// In our case this would be written in matrix form as:
//
//  23 34
//  31 46