Unit test

Google Classroom

Problem

Leila is buying a dinosaur model. The price of the model is $x$x dollars, and she also has to pay a $7\%$7, percent tax.

Which of the following expressions could represent how much Leila pays in total for the model?

Choose 2 answers:

Choose 2 answers:

• (Choice A, Checked, Correct)

  CORRECT (SELECTED)

  $\dfrac{107}{100}x$start fraction, 107, divided by, 100, end fraction, x
• (Choice B, Incorrect)

  INCORRECT

  $0.7x+x$0, point, 7, x, plus, x

  $7\%$7, percent means $7$7 per hundred, which we can write as $0.07$0, point, 07, not as $0.7$0, point, 7.
• (Choice C, Checked, Correct)

  CORRECT (SELECTED)

  $1.07x$1, point, 07, x
• (Choice D, Incorrect)

  INCORRECT

  $x+\dfrac{7}{10}x$x, plus, start fraction, 7, divided by, 10, end fraction, x

  $7\%$7, percent means $7$7 per hundred, which we can write as $\dfrac{7}{100}$start fraction, 7, divided by, 100, end fraction, not as $\dfrac{7}{10}$start fraction, 7, divided by, 10, end fraction.
• (Choice E, Incorrect)

  INCORRECT

  $1.7x$1, point, 7, x

  $7\%$7, percent means $7$7 per hundred, which we can write as $0.07$0, point, 07, not as $0.7$0, point, 7. So when we combine like $x$x-terms, we should add $1$1 and $0.07$0, point, 07 instead of $1$1 and $0.7$0, point, 7.

Hint #11 / 5

The tax is $7\%$7, percent of the price $x$x of the model.

So Leila has to pay $\greenD{7\%\cdot x}$start color #1fab54, 7, percent, dot, x, end color #1fab54 dollars of tax.

Hint #22 / 5

That means that she pays a total of $\greenD{7\%\cdot x}+\maroonD{x}$start color #1fab54, 7, percent, dot, x, end color #1fab54, plus, start color #ca337c, x, end color #ca337c for the model.

Hint #33 / 5

Because $7\%$7, percent means $7$7 per hundred, we can write it in equivalent forms.

$\begin{aligned} 7\%&=\dfrac{7}{100}\\\\ &=0.07 \end{aligned}$

Hint #44 / 5

Let's find equivalent ways of writing the amount Leila pays in total for the dinosaur model.

$\begin{aligned} \blueD{7\%}\cdot x+x&=\blueD{\dfrac{7}{100}}x+x\\\\ &=\left(\blueD{\dfrac{7}{100}}+1\right)x\\\\ &=\dfrac{107}{100}x\\\\ &=\blueD{0.07} x+x\\\\ &=\left(0.07+1\right)x\\\\ &=1.07x \end{aligned}$

Hint #55 / 5

The expressions $\dfrac{107}{100}x$start fraction, 107, divided by, 100, end fraction, x and $1.07x$1, point, 07, x each could represent how much Leila pays in total for the model.