Can someone me with 4 and i’m legitimately struggling.

Problem 4.

In a rectangle, the diagonals are congruent and bisect each other.
You have AC = BD, and AE = CE = BE = DE.
Also each segment of a diagonal is half the length of the diagonal.

AE = BE

2x + 3 = 12 - x

3x = 9

x = 3

AE = 2x + 3 = 2(3) + 3 = 6 + 3 = 9

BD = 2(AE) = 2(9) = 18

Problem 5.

Sides AB and CD are parallel.
Angles BAC and ACD are alternate interior angles of parallel lines, so they are congruent.

m<BAC = m<ACD

3x + 5 = 40 - 2x

5x = 35

x = 7

m<ACD = 40 - 2x = 40 - 2(7) = 40 - 14 = 26

m<BDC = m<ACD = 26

<AED is a remote exterior angle to angles BDC and ACD.

m<AED = m<BCD + m<ACD = 26 + 26 = 52