Answer:
-600
Step-by-step explanation:
4 x 10 x 3 x 5 x -1
40 x 15 x -1
600 x -1 = -600
The equation of direct variation is,
![\begin{gathered} y=kx \\ k=\frac{y}{x} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20y%3Dkx%20%5C%5C%20k%3D%5Cfrac%7By%7D%7Bx%7D%20%5Cend%7Bgathered%7D)
Substitute the values of <em>y</em> and <em>x</em>.
![\begin{gathered} k=\frac{5.4}{4} \\ k=1.35 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20k%3D%5Cfrac%7B5.4%7D%7B4%7D%20%5C%5C%20k%3D1.35%20%5Cend%7Bgathered%7D)
So, the obtained equation will be <em>y</em>=1.35(x).
Let's check with the values of <em>x</em>.
1) If <em>x</em>=4
![\begin{gathered} y=1.35x \\ y=1.35(4) \\ y=5.4 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20y%3D1.35x%20%5C%5C%20y%3D1.35%284%29%20%5C%5C%20y%3D5.4%20%5Cend%7Bgathered%7D)
2) If <em>x</em>=2
![\begin{gathered} y=1.35x \\ y=1.35(2) \\ y=2.7 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20y%3D1.35x%20%5C%5C%20y%3D1.35%282%29%20%5C%5C%20y%3D2.7%20%5Cend%7Bgathered%7D)
3) If <em>x</em>=-2
<span>The least common multiple would be 280 cards of each.
20 Packs of football, 8 packs of Hockey, and 7 packs of Baseball.</span>