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I need help with this question. Solve in y=a•b^x format

I need help with this question. Solve in y=a•b^x format-example-1
User Moondustt
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1 Answer

23 votes
23 votes

Solve the equation in this format:


y=a\mathrm{}b^x

when x = 0, y = 1000


\begin{gathered} y=ab^x \\ 1000=a\mathrm{}b^0 \\ 1000=a\ldots\ldots\text{.}\mathrm{}(1) \end{gathered}

when x = 2, y = 360


\begin{gathered} y=a\mathrm{}b^x \\ 360=ab^2\ldots\ldots..(2) \end{gathered}

solve the equation simulataneously


\begin{gathered} 1000=a\ldots\ldots(1) \\ 360=ab^2\ldots....(2) \\ sub\text{ the value of a in equ(2)} \\ 360=1000b^2 \\ \text{divide both side by 1000} \end{gathered}
\begin{gathered} (360)/(1000)=(1000b^2)/(1000) \\ (36)/(100)=b^2 \\ \text{square the root of both side} \\ \sqrt[]{(36)/(100)}=\sqrt[]{b^2} \\ (6)/(10)=b \\ (3)/(5)=b \end{gathered}

Therefore the equation of the function is


\begin{gathered} y=a.b^x \\ y=1000.((3)/(5))^x \end{gathered}

User XXL
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