
1.
how can find vaiable $y_1,y_2,b_1,b_2$?
How the first matrix divided into smalle matrix$(4*x)$.
The second matrix is then multiplied.
So that the value of variable obtained.
2.
how can do this with matlab?
3.
What is the name of this action?

1.
how can find vaiable $y_1,y_2,b_1,b_2$?
How the first matrix divided into smalle matrix$(4*x)$.
The second matrix is then multiplied.
So that the value of variable obtained.
2.
how can do this with matlab?
3.
What is the name of this action?
I don't know what you mean by $4*x \mid x > 0$, but you can divide the matrix into blocks as $$\left[\begin{array}{@{}cc|cc@{}}1 & 2 & 3 & 4 \\ 5 & 6 & 7 & 8 \\ \hline 9 & 10 & 11 & 12 \\ 1 & 4 & 3 & 1\end{array}\right]\begin{bmatrix}y_1 \\ y_2 \\ 3 \\ 4\end{bmatrix} = \begin{bmatrix}100 \\ 200 \\ b_1 \\ b_2\end{bmatrix}$$ so that you get $$\begin{array}{ccccc} \begin{bmatrix}1 & 2 \\ 5 & 6\end{bmatrix}\begin{bmatrix}y_1 \\ y_2\end{bmatrix} &+& \begin{bmatrix}3 & 4 \\ 7 & 8\end{bmatrix}\begin{bmatrix}3 \\ 4\end{bmatrix} &=& \begin{bmatrix}100 \\ 200\end{bmatrix} \\ \begin{bmatrix}9 & 10 \\ 1 & 4\end{bmatrix}\begin{bmatrix}y_1 \\ y_2\end{bmatrix} &+& \begin{bmatrix}11 & 12 \\ 3 & 1\end{bmatrix}\begin{bmatrix}3 \\ 4\end{bmatrix} &=& \begin{bmatrix}b_1 \\ b_2\end{bmatrix} \end{array}$$ which you can then rearrange to bring all the unknowns to the left-hand side and solve the system.
To find values $y_1,y_2,b_1,b_2$ you should solve following system of four equations in four unknowns :
$$\begin{cases} y_1+y_2+9+16=100 \\ 5y_1+6y_2+21+32=200 \\ 9y_1+10y_2+33+48=b_1 \\ y_1+4y_2+9+4=b_2 \end{cases}$$
[1 2 3 4] [$y_1$ $y_2$ 3 4]$^t$ =100 & [5 6 7 8] [$y_1$ $y_2$ 3 4]$^t$ =200
then $y_1=-39$ & $y_2=57 $
also [9 10 11 12] [-39 57 3 4]$^t$=[100 200 $b_1$ $b_2$] & [1 4 3 1] [-39 57 3 4]$^t$=[100 200 $b_1$ $b_2$]
then $b_1=300$ $b_2=202$
I computed it with matlab.
