Remember that things like this, always need to add up to 180°.
10x+20y=150 is the equation I don't quite understand how she would have money left because she spend $150 for her t-shirts and jeans.
First, we can subtract the discount from the original price. Divide the discount (42%) over 100.
42/100 = 0.42
Next, we need to multiply. It's basically asking what 42% of 20 is.
0.42 × $20 = $8.40
Now, we know that we will have $8.40 on the CD because of the discount. We can subtract the saved amount from the original amount to get the price.
$20 - $8.40 = $11.60
You will pay $11.60 for the CD without taxes.
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Now to add the taxes.... To do this, do the same first step we did when finding the discount price.
6/100 = 0.06
Multiply. Like I said, you can think of it as, '6% of 11.60'.
0.06 × 11.60 = $0.70
Last step is to ADD. Since taxes add more money onto the current price, we will have to add.
$11.60 + $0.70 = $12.30
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The total price of the CD will be: $12.30.
