Question

Which point is on the graph of y = -2x + 1?

A. (2, 7)
B. (3, -8)
C. (6, 8)
D. (4, -7)

Answer 1

D. (4, -7)

Explanation:

To see if a point lands on the graph of a line, substitute the coordinates (x, y) to the x and y in the equation to see if the result is true:

Option A: (2, 7)
Substitute the values in:

`y=-2x+1\\7=-2(2)+1\\7=-4+1\\7=-3`
Not true.
So option A is out.

Option B: (3, -8)

Substitute the values in:

`y = -2x + 1\\-8=-2(3)+1\\-8=-6+1\\-8=-5`

Not true.
So option B is out.

Option C: (6, 8)

Substitute the values in:

`y = -2x + 1\\8=-2(6)+1\\8=-12+1\\8=-11`

Not true.
So option C is out.

Option D: (4, -7)

Substitute the values in:

`y = -2x + 1\\-7=-2(4)+1\\-7=-8+1\\-7=-7`
True.
So point (4, -7) lands on the graph of the line. You can also see this visually in a graphing calculator:
(See picture)