Question

Suppose y varies directly as x and y = 21 when x = 3. find y when x =2

Answer 1

If y varies directly as x, then we can express this relationship using a proportionality constant k, such that:

y = kx

To solve for k, we can use the initial condition given:

y = 21 when x = 3

Substituting these values into the equation above, we get:

21 = k * 3

Solving for k, we get:

k = 7

Now that we have k, we can use the equation to find y when x = 2:

y = kx

y = 7 * 2

y = 14

Therefore, when x = 2, y = 14.

Explanation: