Direct Variation Problems - SAT Math Part 16

TL;DR

This video solves direct and inverse variation problems, providing explanations and step-by-step solutions.

Transcript

56 y varies directly with x if y is 21 when x is 9 what is the value of y when x is 15 so what do we have to do here in this problem well first we need to come up with an equation y varies directly with x so this tells us that y is equal to kx where k is a constant let's say if it stated that y varies indirectly with x or is inversely proportional ... Read More

Key Insights

• 🤩 Direct variation is represented by the equation y = kx, while inverse variation is represented by y = k/x.
• 👈 To find the value of k, divide both sides of the equation by the given x value and simplify.
• 😉 The value of k remains constant in direct and inverse variation problems.
• ❣️ Direct variation shows that as x increases, y also increases or vice versa.
• ❣️ Inverse variation shows that as x increases, y decreases or vice versa.
• 👈 Dividing both sides of the equation by the x value helps calculate the value of k in direct variation problems.
• 👈 Multiplying both sides of the equation by the x value helps calculate the value of k in inverse variation problems.

Questions & Answers

Q: What is direct variation?

Direct variation is a mathematical relationship where y is equal to k times x. As x increases, y also increases, and as x decreases, y decreases.

Q: How do you calculate the value of k in direct variation?

To find the value of k in direct variation, divide both sides of the equation by the given x value. Simplify the expression, and the result will be the value of k.

Q: What is inverse variation?

Inverse variation is a mathematical relationship where y is equal to k divided by x. As x increases, y decreases, and as x decreases, y increases.

Q: How do you calculate the value of k in inverse variation?

To find the value of k in inverse variation, multiply both sides of the equation by the given x value. Simplify the expression, and the result will be the value of k.

Summary & Key Takeaways

• The video explains direct variation, where y is equal to kx, and inverse variation, where y is equal to k/x.

• To find the value of k, divide both sides of the equation by the given x value and simplify.

• Using the calculated value of k, plug in the given x value to find the value of y.