Linear Algebra and Its Applications · Problem 1.3.26

Matrices and Gaussian Elimination — Gilbert Strang

Mathematics · gaussian-elimination

Problem

Solve by elimination the system of two equations

\begin{aligned} x - y &= 0 \\ 3x + 6y &= 18. \end{aligned}

Draw a graph representing each equation as a straight line in the

x

y

plane; the lines intersect at the solution. Also, add one more line—the graph of the new second equation which arises after elimination.