What is the area of the triangle in the in the diagram?

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

X+ y = 5 ; x - y =3 solve using linear combination

Graph a point. start at your origin, move left 10 units, and then move up three units which ordered pair is the point you graphed