Variable y varies directly with variable x. If x = 12, then y = 3. What is the value of y when x = 8?

Step-by-step explanation:

To find the value of y when x = 8 we must first find the relationship between the two variables.

The statement

y varies directly with variable x is written as

y = kx

where k is the constant of proportionality

when

x = 12

y = 3

Substitute the values into the above formula and solve for k

That's

3 = 12k

Divide both sides by 12

So the formula for the variation is

when

x = 8

we have the final answer as

Hope this helps you

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: