Question

the linear equation y=2x represents the cost y of x pounds of pears. which order pair lies on the graph of the equation? A. (2,4) B. (1,0) C.(10,5) D. (4,12)

Answer 1

A. (2, 4)

Explanation:

The ordered pairs represent (x, y). Since you have y =2x, this is the same as ...

(x, 2x)

That is, the second number in the pair needs to be twice the first number in the pair. Since you know your times tables, you know that this is not the case for (1, 0), (10, 5) or (4, 12). Those values of x would give (1, 2), (10, 20), (4, 8).

It is the case that you have (x, 2x) for (2, 4).

The point (2, 4) lies on the graph of y = 2x.