Matrix Composition: J○H & Solving z=J○Hx

[calcuseless]

Homework Statement

J represents a 3x2 matrix and H represents and 2x4 matrix. y = Hx and z = Jy, where y is a 2x1 matrix, z is a 3x1 matrix, and x is a 4x1 matrix. Form the composition J○H and simplify z = J○Hx.

The Attempt at a Solution

I don't know what my answer is going to look like because I don't know what a composition of matrices represents. Is it the same as matrix multiplication?

 

[LCKurtz]

Homework Statement

J represents a 3x2 matrix and H represents and 2x4 matrix. y = Hx and z = Jy, where y is a 2x1 matrix, z is a 3x1 matrix, and x is a 4x1 matrix. Form the composition J○H and simplify z = J○Hx.

The Attempt at a Solution

I don't know what my answer is going to look like because I don't know what a composition of matrices represents. Is it the same as matrix multiplication?

Yes. And if the matrices are conformable (the right dimensions) you can multiply them.