Label each pair of triangles with the postulate or theorem that proves the triangles are congruent.

We can conclude that Δ ABC ≅ Δ DEF by AAS postulate.

Step-by-step explanation:

Δ ABC and Δ DEF are congruents because:

1. Their non-included sides BC and EF are equal (7 units = 7 units)

2. Their angles ∠A and ∠D are equal (39° = 39°)

3. Their angles ∠C and ∠F are equal  (64° = 64°)

Now, we can conclude that Δ ABC ≅ Δ DEF by AAS postulate.

x= -3

step-by-step explanation:

step 1: simplify brackets

4 - x - 1 = 6

step 2: simpilfy

3 - x = 6

step 3: subtract 3 from both sides

-x = 6 - 3

step 4: simpilfy 6 - 3

-x = 3

step 5: multiply both sides by -1

x = -3