Answer:
x = 17
Step-by-step explanation:
Since ΔIJK ≅ ΔPQR then ∠I ≅ ∠P, that is
3x + 4 = 72 - x ( add x to both sides )
4x + 4 = 72 ( subtract 4 from both sides )
4x = 68 ( divide both sides by 4 )
