$\"\"$

\

Consider $\"\"$ is the amount invested in treasury bills.

\

$\"\"$ is the amount invested in treasury bonds.

\

$\"\"$ is the amount invested in corporate bonds.

\

The total investment equation is $\"\"$ .

\

Annual income equation is $\"\"$ .

\

Condition on investment equation is $\"\"$ .

\

$\"\"$ .

\

Definition of augment matrix :

\

If $\"\"$ are the system of equations then the augmented matrix is $\"\"$ .

\

Augment matrix of the system of equations is $\"\"$ .

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Apply $\"\"$ and $\"\"$ .

\

$\"\"$

\

Apply $\"\"$ .

\

$\"\"$

\

Apply $\"\"$ and $\"\"$

\

$\"\"$

\

Apply $\"\"$ .

\

$\"\"$

\

Apply $\"\"$ and $\"\"$ .

\

$\"\"$ .

\

Therefore, carletta should invest $\"\"$ in treasury bills, $\"\"$ in treasury bonds and $\"\"$ in corporate bonds.

\

$\"\"$

\

Carletta should invest $\"\"$ in treasury bills, $\"\"$ in treasury bonds and $\"\"$ in corporate bonds.