Answer:
x = 10
Explanation:
The diagonals of a rectangle are equal in length and bisect each other
⇒ JL = KM and
JN = LN = KN =MN
ΔJMN is an isosceles triangle since JN = MN
This means that the angles opposite to equal sides are equal
⇒ ∠JMN = ∠MJN
⇒ 7x - 2 = 3x + 38
⇒ 7x - 3x = 38 + 2
⇒ 4x = 40
⇒ x = 10