Answer:
He has 1 7/12kg of plant food left.
Step-by-step explanation:
How much plant food did he use?
1 2/3 + 1/4
5/3 + 1/4
20/12 + 3/12 = 23/12
How much does he have left?
3 1/2 - 23/12
7/2 - 23/12
42/12 - 23/12 = 19/12 = 1 7/12kg left
The plant food left with Sheldon is [tex]1\dfrac{7}{12}[/tex] kg.
[tex]3\dfrac{1}{2}= \dfrac{(3 \times 2)+1}{2} = \dfrac{7}{2}[/tex] kg
[tex]1\dfrac{2}{3}= \dfrac{(1 \times 3)+2}{3} = \dfrac{5}{3}[/tex] kg
= Plant food used on strawberry plants + Plant food used on tomato plants
[tex]=\dfrac{5}{3}+\dfrac{1}{4}\\\\ =\dfrac{(5\times 4)}{(3\times 4)} + \dfrac{(1\times 3)}{(4\times 3)}\\\\ =\dfrac{20}{12}+\dfrac{3}{12}\\\\ =\dfrac{20+3}{12}\\\\ =\dfrac{23}{12}[/tex]
Thus, plant food already used by Sheldon is [tex]\dfrac{23}{12}[/tex] kg.
Plant food left with Sheldon
= Plant food bought by Sheldon - Plant food used by Sheldon
[tex]=\dfrac{7}{2} - \dfrac{23}{12}\\\\ =\dfrac{(7 \times 6)}{(2\times 6)}-\dfrac{23}{12}\\\\ = \dfrac{42}{12}-\dfrac{23}{12}\\\\ =\dfrac{42-23}{12}\\\\ =\dfrac{19}{12}\\\\ =1\dfrac{7}{12}[/tex]
Hence, the plant food left with Sheldon is [tex]1\dfrac{7}{12}[/tex] kg.
Learn more about fractions:
https://brainly.com/question/151276
