Question

Write the direct variation of the equation if y varies directly with x and y = 45 when x = 9.

Answer 1

Direct variation equation: y=kx

Answer 2

So it's pretty much saying to plug in values, and solve for k

Answer 3

Since, y varies directly with x
Mathematically it can be written as
\[y \alpha x \rightarrow y=kx...(k=constant)\]
Now at y = 45 and x = 9, k=?
\[45 = k \times 9 \rightarrow k= \frac{45}{9} \rightarrow k=5\]
substituting k=5 in y=kx we find
y=5x, which is the required equation of the direct variation.

Answer 4

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