Answer:
mDF = 18
Step-by-step explanation:
DE and EF must add up to DF.
Step 1: Set up equation
mDE + mEF = mDF
x + 7 + 7 = 4x + 2
Step 2: Solve for x
- Combine like terms: x + 14 = 4x + 2
- Subtract x on both sides: 14 = 3x + 2
- Subtract 2 on both sides: 12 = 3x
- Divide both sides by 3: 4 = x
- Rewrite: x = 4
Step 3: Find mDF
mDF = 4x + 2
mDF = 4(4) + 2
mDF = 16 + 2
mDF = 18
