Question

Which of the lines graphed in the diagram represents the equation

x + 3y = 3?














A.


line a











B.


line b











C.


line c











D.


line d

Answer 1

Write the line in y = mx + b form.

x + 3y = 3
3y = -x + 3
y = ( -1/3) x + 1

Observe that the line has a negative slope. That means as you look at the graph from left to right, the line fall.

Look at the options and see if there is a falling line. In the next space, I'll sketch how a falling line looks in case that is not clear.