x+1 dm 3 sm = 6 dm 4 sm : 2

Interpret units: dm = decimeter, sm = centimeter (1 dm = 10 sm).

1. Compute the right-hand side: (6 dm 4 sm) ÷ 2 = (64 cm) ÷ 2 = 32 cm = 3 dm 2 sm.

2. Solve for x: x + 1 dm 3 sm = 3 dm 2 sm x = (3 dm 2 sm) − (1 dm 3 sm) = 32 cm − 13 cm = 19 cm 19 cm = 1 dm 9 sm.

Answer: x = 1 dm 9 sm. (Check: 1 dm 9 sm + 1 dm 3 sm = 3 dm 2 sm, which matches 6 dm 4 sm ÷ 2.)