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43 votes
43 votes
= 186x – 30y5х – 25y= 15

User Oscarmorasu
by
2.6k points

1 Answer

17 votes
17 votes

Answer:

There are infinitely many solutions

Step-by-step explanation:

Given the system of linear equations:


\mleft\{\begin{aligned}6x-30y=18 \\ 5x+25y=15\end{aligned}\mright.

To solve using Matrices, we write the equation in the form:

Ax = b

Where A represent the matrix of the coefficient of the variables x and y

x represent the matrix of the variables x and y

and b represents the matrix of the constants on the right hand side.

In matrix form, we have:


\begin{bmatrix}{6} & {-30} \\ {5} & {-25}\end{bmatrix}\begin{bmatrix}{x} \\ {y}\end{bmatrix}=\begin{bmatrix}{18} \\ {15}\end{bmatrix}

We must have a nonzero determinant for A

The determinant of A is:


\begin{gathered} (-25*6)-(-30*5) \\ =-150+150 \\ =0 \end{gathered}

The determinant of A is zero, without going far, we conclude that the system has infinite number of solutions.

User SusanW
by
3.0k points
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