box1: y-axis
box2: dilation
box3:7
Step-by-step explanation
![\begin{gathered} Let\text{ } \\ (x,y)\text{ the initial image} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/p1il7ehv84r6cbkyomkpbhi20bmlu30jw5.png)
Step 1
![(x,y)\rightarrow(-x,y)](https://img.qammunity.org/2023/formulas/mathematics/college/ikcitr9ov18gnuy0131ezdtc936qt485rg.png)
we can see y coordinate is the same, but x coordiante has opposite sign(its sign is changed)
hence
When you reflect a point across the y-axis, the y-coordinate remains the same, but the x-coordinate is transformed into its opposite (its sign is changed),so for box 1 the answer is
y-axis
Step 2
![(x,y)\rightarrow(0.5x,0.5y)](https://img.qammunity.org/2023/formulas/mathematics/college/cigua1yv9d82dr9031x6qqkm4my9q6yru7.png)
A dilation (similarity transformation) is a transformation that changes the size of a figure. It requires a center point and a scale factor , k
in this case k=0.5
![\begin{gathered} (x,y)\rightarrow(kx,ky) \\ (x,y)\rightarrow(0.5x,0.5y) \\ so \\ k=0.5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ilcvpi7766uszf45631ypvwtcpyogf7iju.png)
so, for box 2, the answer is dilation
Step 3
![(x,y)\rightarrow(x-7,y+7)](https://img.qammunity.org/2023/formulas/mathematics/college/i4diyxgf1z4ctuaayzxbguqdx2wkkiqf00.png)
when you traslate horizontally , you affect the x coordinates, so
![\begin{gathered} x+k\rightarrow moves\text{ the xcoordiantes k espaces to the rigth} \\ x-k\rightarrow moves\text{ the xcoordiantes k espaces to the left} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/yzmukn7saa42tvjkfp5ij56pvvub00ktdw.png)
hence, in this case
![(x-7)\rightarrow the\text{ figure is traslated 7 units to the left}](https://img.qammunity.org/2023/formulas/mathematics/college/ftc7k6hvbp836e5qfbnb1i7ekbcbp052pf.png)
and
when you traslate the figure vertically, you move on y axis, it means
![\begin{gathered} y+k=\text{moves the shape up} \\ y-k=\text{moves the shape down} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/7xafx2l3v6j7su2hiyuuwgt20nexk3w23h.png)
hence, in this case
![y+7\rightarrow th\text{e figure is traslated 7 units up}](https://img.qammunity.org/2023/formulas/mathematics/college/af43kjdguhuasx2ksifqeb0fq7uepmewhf.png)
I hope this helps you