When using the box method, it's really helpful to write equations. For example in this equation, let's set the value on top of the top left box (left of the "1") as x.
So,
k * x = 5k²
Divide both sides by k
x = 5k
Set the other unknown factor (the one below "k") as y.
So,
y * 1 = -7
y = -7
Now, solve for the missing products:
k * 1 = k
5k * (-7) = -35k
I hope this helps! Feel free to ask any questions!
