Solve the following system of equations using \, compute and display the error vector (x=A\b is the same as x-inv(A)*b and error = abs(A*x1-b) ). 3a + 6b + 4c = 1 a + 5b = 2 7b + 7c = 3

4. In MATLAB, plot the curve of the quadratic equation 3x2 - 9x - 12 = 0. Both the roots of the equation should be visible in the plot.

Plot the lines y1 = 2x + 5 and y2 = 9x - 3 in MATLAB. The x-axis should be from -10 to 10.

What does the term "homoscedasticity" mean?