Q. If x and y are in direct proportion and y is 5 when x is 15 , find y when x is 6 .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 of Variation: Use the given values to find the constant of variation k. We know that y=5 when x=15. Substitute these values into the direct variation equation to find k. 5=k×15
Solve for k: Solve for k.Divide both sides of the equation by 15 to isolate k.k=155k=31
Write Updated Equation: Write the direct variation equation with the found value of k. Now that we have found k to be 31, we can write the direct variation equation as y=(31)x.
Find y for x=6: Use the direct variation equation to find y when x is 6. Substitute x=6 into the equation y=31x. y=31×6y=2
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