Answer:
18 cm; 30 cm
Step-by-step explanation:
If you reduce the longer length by 12 cm, then the two boards would total ...
48 cm -12 cm = 36 cm
That is double the length of the smaller board, so it must be 18 cm.
The longer board is 12 cm longer, so is 30 cm.
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Check
The total length is 18 cm + 30 cm = 48 cm.
