Answer:
x = 1
Explanation:
Given that:
∆ABC ≅ ∆ DEF By S.A.S. axiom
If two triangles are congruent, then they have the same length sides and the same measure angles.
Over here:
The side opposite the angle is congruent.
So,
BC = EF
Substitute the known value:
13x - 12 = 7x - 6
Subtract 7x on both sides.
13x - 12 - 7x = 7x - 6 - 7x
6x - 12 = - 6
Add 12 on both sides.
6x - 12 + 12 = - 6 + 12
6x = 6
Divide both sides by 6.

x = 1
Therefore, the value of x is 1.