Variable d represents the time per minute Lilianna spends in the park.
Explanation:
Lilianna uses \frac{3}{4} calories per minute just by sitting. She uses 1 more calorie per minute by walking.
Liliana uses a total of 12\frac{1}{4} calories walking to the park.
Lilianna uses the equation, d(\frac{3}{4}+1)=12\frac{1}{4} to represent the situation.
Here, variable d represents the time per minute she spends in the park.
and is given as,
d(\frac{3}{4}+1)=12\frac{1}{4}
It can be written as,
d(\frac{3}{4}+1)=\frac{49}{4}
Solving for d,
d(\frac{3}{4}+1)=\frac{49}{4}
\Rightarrow d(\frac{3+4}{4})=\frac{49}{4}
\Rightarrow d(\frac{7}{4})=\frac{49}{4}
\Rightarrow d=\frac{49 \times 4}{4 \times 7}
\Rightarrow d=7
Thus, she spend d= 7 minutes total to the park.