To reflect a plane on the plane x1x3, you would first find the equation of the plane you want to reflect. Then, you would substitute x2 with -x2 in the equation to reflect it across the x1x3 plane. This means changing the sign of the coefficient of x2 in the equation of the plane. The resulting equation will be the reflection of the original plane across the x1x3 plane. **

To reflect a plane across the plane x1x3, you can first find the equation of the mirror plane x1x3. Then, for each point on the original plane, you can find its reflection across the mirror plane by using the formula for reflecting a point across a plane. This involves finding the perpendicular distance from the point to the mirror plane and then using that distance to find the reflected point. By applying this process to all points on the original plane, you can obtain the reflected plane across the x1x3 plane. **

The choice between a free market economy and a planned economy depends on the specific goals and values of a society. A free market economy allows for individual freedom and competition, which can lead to innovation and efficiency. However, it can also result in inequality and lack of regulation. On the other hand, a planned economy allows for more control and distribution of resources, but it can stifle individual initiative and innovation. Ultimately, the decision between the two depends on the balance a society seeks between individual freedom and social equality. **

The answer to this question depends on one's perspective and values. A social market economy combines elements of both a free market and government intervention to ensure social welfare and economic stability. It aims to balance individual freedom with social responsibility. On the other hand, a free market economy prioritizes individual freedom and minimal government intervention, allowing for more competition and innovation. Ultimately, the "better" system depends on the specific needs and values of a society, as well as the balance between individual freedom and social welfare that is desired. **

To determine a parallel plane to a given plane, you can use the normal vector of the given plane. If the normal vector of the given plane is (a, b, c), then the parallel plane will have the same normal vector. You can then use this normal vector to find the equation of the parallel plane. If the given plane has the equation Ax + By + Cz + D = 0, then the parallel plane will have the equation Ax + By + Cz + K = 0, where K is a constant. This will ensure that the two planes are parallel to each other. **

Online commerce refers to the buying and selling of goods and services over the internet, while retail commerce refers to the traditional brick-and-mortar stores where customers can physically visit and make purchases. Online commerce offers the convenience of shopping from anywhere at any time, while retail commerce provides the opportunity for customers to see, touch, and try products before making a purchase. Online commerce often involves lower overhead costs and can reach a wider audience, while retail commerce provides a more personalized and immediate shopping experience. **

A social market economy combines elements of both a free market economy and a planned economy. It allows for private ownership of businesses and resources, while also implementing government regulations to ensure fair competition and social welfare. In contrast, a free market economy relies on minimal government intervention, allowing businesses to operate with little regulation. On the other hand, a planned economy is centrally controlled by the government, with decisions regarding production, distribution, and pricing made by central authorities. **

To establish a parallel plane to the x1-x2 plane, one can use the equation of the x1-x2 plane, which is typically written as z = 0. To create a parallel plane, one can simply add or subtract a constant value from the right-hand side of the equation. For example, to create a parallel plane that is 3 units above the x1-x2 plane, the equation would be z = 3. This will create a new plane that is parallel to the x1-x2 plane and shifted vertically by 3 units. **