Tran says that -1/4x - 7 + 9/4x + 2x is equivalent to 4x - 7. how can substituting any value for x you determine whether train is correct? is tran correct? use substitution to justify your answer.

Yes, Tran is correct .

By substituting different values for x, we can see that -7 + + 2x is equivalent to 4x-7.

Step-by-step explanation:

Lets substitute x = 1 in -7 + + 2x

⇒   -7 + + 2(1)

⇒   -7 + + 2

⇒ -3.

Now, substitute x = 1 in 4x-7.

⇒ 4(1) - 7 = -3.

⇒ we got -3 in both the cases.

Now let us substitute x = 2 in   -7 + + 2x

⇒   -7 + + 2(2).

⇒ - 7 + + 4.

⇒ 1.

now, x =2 in 4x -7.

⇒ 4(2) - 7 = 1.

⇒ we got 1 in both the cases.

Not only these values, for any value of x both the expressions give same value, because, -7 + + 2x is equivalent to 4x-7.

-7 + + 2x

= -7 + + 2x

= -7 + 2x + 2x.

= 4x-7.