Answer: the dwarf tree grew by 3 inches.
the semi dwarf tree grew by 6 inches.
the full size tree grew by 18 inches.
Step-by-step explanation:
Let x represent how much the semi-dwarf lemon tree grew.
Last month, a dwarf lemon tree grew half as much as a semi-dwarf lemon tree. This means that the amount by which the dwarf lemon tree grew is expressed as x/2
A full-size lemon tree grew three times as much as the semi-dwarf lemon. This means that the amount by which the full-size lemon tree grew is expressed as 3x
Together, the three trees grew 27 inches. This means that
x/2 + x + 3x = 27
Cross multiplying by 2, it becomes
x + 2x + 6x = 54
9x = 54
x = 54/9
x = 6 inches
The dwarf tree grew by 6/2 = 3 inches.
The full-size lemon tree grew by 3 × 6 = 18 inches
