Question 65760
When you write that triangle ABC = triangle DEF, I expect you mean "congruent to", in which case the corresponding sides of the two triangles are congruent (equal). This means, of course, that side DF is equal to side AC, so you can write:
2n+4 =4n-8 because DF = 2n+4 and AC = 4n-8. Simplify this and solve for n.
Subtracting 2n from both sides, you get:
4 = 2n-8  Now add 8 to both sides.
12 = 2n Finally, divide both sides by 2.
n = 6