WILL MARK YOU BRAINLIEST

Answer:
ABCD is a rhombus => AC is perpendicular with BD
=> AC = 2(2n + 5) = 30
<=> 2n + 5 = 15
=> n = 5
with n = 5 => AC/2 = 15
BD/2 = 4.5 - 3 = 17
BC² = (AC² + BD²)/4 = 514/4 = 128.5
=> BC = 11.34
Answer:
Step-by-step explanation:
The question is what does 2n + 5 represent? Is it 1/2 the line or all of AC. There seems to be a run on ambiguous questions. I'm going to assume that 2n + 5 is AC -- all of it. And 4n-3 is all of BD.
AC = 30
2n + 5 = 30 Subtract 5 from both sides.
2n = 30 - 5
2n = 25 Divide by 2
n = 25/2
n = 13.5
====================
BD = 4n - 3
BD = 4*13.5 - 3
BD = 54 - 3
BD = 51