## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

If the coordinates of the given point satisfies the line's equation, then it is on the line. Substitute the x and y coordinates of the point into the equation to have: $2x+y=4 \\2(1) + 2 = 4 \\2+2=4 \\4=4$ The coordinates of the point satisfy the equation. Thus, the point (1, 2) is on the line $2x+y=4$ so the given statement is true.