Chapter 8.10, Problem 7OE

To determine

To find:

The equation given that the statement

Answer to Problem 7OE

The equation is $P=kw$

Explanation of Solution

Given:

  $c_1,c_2$ varies directly as $d_1,d_2$

Concept used:

If the quantities $x$ and $y$ are related by an equation

  $y=kx$

For some constant $k\ne 0$

That is y varies directly as $x$ or y is directly proportional to $x$

The constant $k$ is called constant proportionality

Calculation:

If the quantities $c_1,c_2$ and $d_1,d_2$ are related by an equation

  $\frac{c_1}{d_1}\alpha \frac{1}{d_2}$

  $\frac{c_1}{d_1}=\frac{c_2}{d_2}$

For some constant $k\ne 0$

That is $c_1,c_2$ varies directly as $d_1,d_2$ or $c_1,c_2$ is directly proportional to $d_1,d_2$

The constant $k$ is called constant proportionality