Systems as Matrix Equations

Three equations, three unknowns — a tangle of x's, y's, and z's. But each equation is just a dot product: the row of coefficients times the unknown vector equals the right-hand side. Stack the rows into a matrix A, and the whole system becomes a single equation, Ax = b. That compactness is why every scientific computing library, every neural network, and every economic model speaks in matrix equations.