Question

If x varies directly with y and x= 5 when y =10. Find the value of x when y= 16? a) 8 b) 7 c) 9 d) 10​

Answer 1

$\begin{lgathered}\frak{Given}\begin{cases}&\sf{x\:varies\:directly\:with\:y}\\ \ &\sf{x=5\:and\:y=10}\end{cases}\end{lgathered}$

❍ To find :- Value of x when y = 16

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Solution:-

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⠀⠀⠀⠀⠀⠀${:\implies{\sf{x ∝ y \implies x = ky \: ( Where\:k\:is\:a\:constant )}}}$

⠀⠀⠀⠀⠀⠀${:\implies{\sf{x = 5 \:\: when\:y = 10}}}$

⠀⠀⠀⠀⠀⠀${:\implies{\sf{ 5 = k × 10}}}$

⠀⠀⠀ ⠀⠀⠀${:\implies{\sf{k =\dfrac{5}{10}}}}$

⠀⠀⠀⠀⠀⠀${:\implies{\sf{k = \dfrac{1}{2}}}}$

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⠀⠀⠀⠀⠀⠀⠀When , y = 16 then

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⠀⠀⠀⠀⠀⠀${:\implies{\sf{x = ky}}}$

⠀⠀⠀⠀⠀${:\implies{\sf{x = \dfrac{1}{2}×16}}}$

⠀⠀⠀⠀⠀⠀${:\implies{\sf{\boxed{\pink{x\:=8}}}}}$

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$\therefore{\underline{\textsf{Hence,the value of x is \textbf{8}\:when\:y=16}}}$