Chapter 8, Problem 11PT

(a)

To determine

To write: an equation to find the profit per plant sold.

Answer to Problem 11PT

The equation is: $y=4.8x$

Explanation of Solution

Given:

The school earns $57.60 when 12 plants are sold.

Calculation:

The amount earns is denoted y and number of plotted plant is denoted by x

Now, if there is direct variation then there is some constant variable k such that it satisfies the equation: $y=kx$

So, put the value of $x=12$ and $y=57.60$ in equation to find the value of k

  $57.60=12k$

Divide both sides by 12.

  $\begin{array}{c}\frac{57.60}{12}=\frac{12k}{12}\\ 4.8=k\end{array}$

Use k to write an equation.

  $y=4.8x$

Conclusion:

Therefore, the equation is: $y=4.8x$

(b)

To determine

To find: The total profit earned when 65 plants are sold

Answer to Problem 11PT

The total profit earned when 65 plants are sold is $312

Explanation of Solution

Calculation:

Now, in order to calculate profit if 65 plants are sold, put the value of $x=65$ in equation.

  $\begin{array}{c}y=4.8\left(65\right)\\ =312\end{array}$

Conclusion:

Therefore, the total profit earned when 65 plants are sold is $312