[tex]\boxed{\underline{\bf \: ANSWER}}[/tex]
[tex] \sf \: \frac{1}{4s} = 15 \\ [/tex]
Variable s cannot be equal to 0 as division by zero is not defined. Multiply both sides of the equation by 4s.
[tex] \sf \: 1=60s [/tex]
Swap sides so that all variable terms are on the left-hand side.
[tex] \sf \: 60s=1 [/tex]
Divide both sides by 60.
[tex] \sf \: s= \boxed{ \bf\frac{1}{60}}\:\sf\approx 0.0166... \\ [/tex]
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Hope it helps.
гคเภ๒๏ฬรคlt2222