Question

Please help with this easy question!
I have these 3 equations:
y*z = lambda*b*c
x*z = lambda*a*c
x*y = lambda*a*b

the solution shows that they become:

x*y*z = lambda*b*c*x
x*y*z = lambda*a*c*y
x*y*z = lambda*a*b*z

How do they go from the 3 equations to that step? I attached a screenshot too.