When converting a linear equation into an augmented matrix, which equation form is needed

For this case, what you need is to write an equation of the form:
 Ax = b
 Where
 A = coefficient matrix of the unknowns of the linear system of equations.
 x: unknowns vector
 b: vector solution of each equation of the linear system.
 The augmented matrix is
 (A l b)
 answer
 Ax = b
 Augmented matrix:
 (A l b)

Ibelieve it is

300b(x) is graphed by the functio