Q. If x and y vary directly and y is 25 when x is 5 , find y when x is 10 .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=25 when x=5. Substitute these values into the direct variation equation to find k. 25=k×5
Solve for k: Solve for k.Divide both sides of the equation by 5 to isolate k.525=kk=5
Write with k: Write the direct variation equation with the found value of k. Now that we know k=5, the direct variation equation is y=5x.
Find y: Use the direct variation equation to find y when x=10. Substitute x=10 into the equation y=5x. y=5×10y=50
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