Q. If x and y are in direct proportion and y is 1 when x is 4 , find y when x is 12 .Answer: y=
Write Equation: Write the equation that represents the direct variation between x and y. Since y varies directly with x, the equation can be written as y=kx, where k is the constant of variation.
Find Constant: Use the given values to find the constant of variation k. We know that y=1 when x=4. Substitute these values into the direct variation equation to find k. 1=k×4
Solve for k: Solve for k.Divide both sides of the equation by 4 to isolate k.k=41
Write with k: Write the direct variation equation with the found value of k. Now that we have found k to be 41, we can write the direct variation equation as y=(41)x.
Find y for x=12: Use the direct variation equation to find y when x is 12. Substitute x=12 into the equation y=41x to find y. y=41×12
Calculate y: Calculate the value of y.y=3
More problems from Write and solve direct variation equations