Well, I'm having trouble on some of my homework questions and looking to get help as soon as possible on one of them about inverse variation.
1. If y varies inversely as x and y = -3 when x = 9, find y when x = 81.
I will use the equation y = k/x but I have no idea how to plug the numbers in and then solve ;/
-3/9 = y/81
Solve for y.
You sure its not -3/81 = y/9?
My answer came out as -1/3 and I solved in 2 different ways.
UR right
To solve this problem, you need to use the given equation for inverse variation, which is y = k/x.
Step 1: Plug in the values given in the problem. You are given that when x = 9, y = -3. So, you can write the equation as -3 = k/9.
Step 2: Solve for the constant of variation, k. Multiply both sides of the equation by 9, so -3(9) = k, which gives k = -27.
Step 3: Now that you have the value of k, you can use it to find the value of y when x = 81. Plug in the values into the equation: y = (-27)/81.
Step 4: Simplify the expression: y = -27/81 = -1/3.
Therefore, when x = 81, y = -1/3.
To summarize, you first need to find the constant of variation, k, by plugging in the given values of x and y. After finding k, you can then use it to solve for the desired y-value by substituting the given x-value into the equation.