Answer:
a) x + 10 = 45
b) 3 = 6 - x
c) d = s * t
Step-by-step explanation: This is actually pretty simple. Let's put down one theorem.
SYMMETRIC THEOREM OF PROPERTIES: If a equals b, then b must equal a. Thus, a = b and b = a.
This is all we're really doing.
Take a) for example, 45 = x + 10. Let's label (45) as A, and (x + 10) as B. Thus we have A = B. Now we know by the Symmetric Property, we have B = A. Thus, substituting B and A again, we get x + 10 = 45.
Just keep doing this with all the equations.
Hope this helped!