Let's calculate how much for the $12 t - shirt after the discount.
First, convert 40% into a decimal,
![40\% = 0.4](https://tex.z-dn.net/?f=40%5C%25%20%3D%200.4)
Next, multiply the cost by the discount,
![12 \times 0.4 = 4.8](https://tex.z-dn.net/?f=12%20%5Ctimes%200.4%20%3D%204.8)
Lastly, subtract the amount discounted,
![12 - 4.8 = 7.2](https://tex.z-dn.net/?f=12%20-%204.8%20%3D%207.2)
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Now
Let's calculate the amount after the sales tax,
First convert 9% to a decimal,
![9\% = 0.09](https://tex.z-dn.net/?f=9%5C%25%20%3D%200.09)
Next, multiply the cost of the t - shirt by the sales tax,
![7.2 \times 0.09 = 0.648 = 0.7](https://tex.z-dn.net/?f=7.2%20%5Ctimes%200.09%20%3D%200.648%20%3D%200.7)
Lastly, add the amount of sales tax to the price of the t - shirt,
![7.2 + 0.7 =7.9](https://tex.z-dn.net/?f=7.2%20%2B%200.7%20%3D7.9)
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Answer : the t - shirt will be $7.90 after everything.
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I hope that helps you out!!!
Any more questions, please feel free to ask me and I will gladly help you out!!!
~Zoey