Sagot :
DIRECT VARIATION
[tex]\red{\overline{\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad}}[/tex]
MATHEMATICAL STATEMENT:
- y varies directly as x
EQUATION:
- y = kx
where k is the constant of the variation
GIVEN:
- y = - 18 when x = 9
UNKNOWN:
- constant of the variation k
- y when x = 7
SOLUTION:
First we have to find the value of k using the given values.
[tex] \tt y = kx \\ \\ \tt - 18 = k(9) \\ \\ \tt - 18 = 9k \\ \\ \tt \frac{ - 18}{9} = \frac{9k}{9} \\ \\ \boxed{ \tt k = - 2}[/tex]
Now that we have the value of k, we can already find y when x = 7
[tex] \tt y = kx \\ \\ \tt y = ( - 2)(7) \\ \\ \tt \boxed{ \red{ \tt y= - 14}}[/tex]
∴ y = - 14 when x = 7
[tex]\red{\overline{\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad}}[/tex]
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