Original Height = 36 inches.
Change in height:
[tex]44\dfrac{3}{4} - 36 = 8\dfrac{3}{4} [/tex]
Number of years :
[tex]8\dfrac{3}{4} \div 1\dfrac{1}{4} [/tex]
[tex]=\dfrac{35}{4} \div \dfrac{5}{4} [/tex]
[tex]=\dfrac{35}{4} \times \dfrac{4}{5} [/tex]
[tex]=7[/tex]
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Answer; Derek has planted the tree for 7 years.
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