m∠JKL = m∠DKL + m∠JKD
We have m∠JKL = 2x + 141, m∠DKL = x + 56 and m∠JKD = 85°. Substitute:
2x + 141 = x + 56 + 85
2x + 141 = x + 141 subtract 141 from both sides
2x = x subtract x from both sides
