Question

Ming drew a triangle. The sum of the angles of the triangle is 180º.

Answer 1

Answer: The second matrix

If we want to write a proper matrix to represent the given system of equations, we have to arrange it in order:

$a+b+c=180$

$2a-b+0c=0$

$4a+0b-c=-5$

After this, we can write the matrix with the coefficients of each equation:

$\left[\begin{array}{ccc|c}1&1&1&180\\2&-1&0&0\\4&0&-1&-5\end{array}\right]$

Being this, the matrix that represents the measure of each angle in Ming's triangle