Answer:
mDE = 9
Step-by-step explanation:
mCD and mDE must add up to mCE
Step 1: Set up equation
mCD + mDE = mCE
5x + 1 + 3x + 3 = 20
Step 2: Solve for x
- Combine like terms: 8x + 4 = 20
- Subtract 4 on both sides: 8x = 16
- Divide both sides by 8: x = 2
Step 3: Find mDE
mDE = 3x + 3
mDE = 3(2) + 3
mDE = 6 + 3
mDE = 9
