Answer:
x = 5
Explanation:
A rhombus is a quadrilateral in which all sides are equal.
Since ABCD is a rhombus, therefore:
AB = BC
3x - 4 = 2x + 1
3x - 2x = 1 + 4
x = 5
We can check:
AB = 3(5) - 4 = 11 units
BC = 2(5) + 1 = 11 units
They are equal
Hope this helps :)
