\( 15=\square \) groups of 4 remainder \( \square \)

In the previous steps, we have determined \( n=7, \sum x y=84.5, \sum x=28, \sum y=26, \sum x^{2}=140, \sum y^{2}=111 \). Now, just substitute each of these valyes into the formula for \( r \) and simplify. Enter the results in the box below. Round your answer to six decimal places. \[ r=\frac{n \sum x y-\left(\sum x\right)\left(\sum y\right)}{\sqrt{n x^{2}-\left(\sum x\right)^{2}} \sqrt{n \sum y^{2}-\left(\sum y\right)^{2}}} \]

1 To find 4 times any nurber, Sayua uses doubling (multiplying by 2 , then by 2 agan), a Show how Sayua would solve \( 4 \times 9 \) ? b What is another way to solve \( 4 \times 9 \) ?

Test Prep 9 A shop owner wants to buy a new laptop. The laptop costs \( \$ 1,485 \). How many weeks will the owner have to save if he saves \( \$ 50 \) each week? \( \begin{array}{lll}\text { HMH } 20 \text { weeks } & \text { (B) } 29 \text { weeks } & \text { (C) weeks }\end{array} \)

\( \begin{array}{ll}\text { I. Factoriza los } & \text { 1. } x^{2}-20 x+64= \\ \text { siguientes trinomios. } & \text { 2. } x^{2}-6 x+8= \\ \text { (3p). } & \text { 3. } 12+7 x+x^{2}= \\ & \text { 4. } 12-7 x+x^{2}= \\ & \text { 5. } 2 x^{2}+3 x-2= \\ & \text { 6. } 20 x^{2}+x-1=\end{array} \)

Shade \( \frac{3}{4} \) of the rectangle. Explain of show your reasoning.