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.You saved $200 on your new laptop because you bought it online. If this was a 20% savings from the original price, find the originalcost of the laptop.The original cost of the laptop was

User Sauleil
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1 Answer

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so, the original cost was $100

Step-by-step explanation

the easiest way to solve this is by using a rule of three

then

Step 1

Let

orginal price=100% = unknow value= x

aved= 20%=$200,

Step 2

make the proportions and solve for x


\begin{gathered} \text{if } \\ x\rightarrow100 \\ \text{then} \\ 200\rightarrow20 \\ \end{gathered}

the ratios are equals, so the proportion is


(x)/(100)=(200)/(20)

finally, isolate x


\begin{gathered} (x)/(100)=(200)/(20) \\ cross\text{ multiply} \\ 20\cdot x\text{=10}0\cdot200 \\ 20x=20000 \\ \text{divide both sides by 20} \\ (20x)/(20)=(20000)/(200) \\ x=20 \\ x=100 \end{gathered}

so, the original cost was $100

I hope this helps you

User David Homes
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