Answer:
x - 4
Step-by-step explanation:





Answer:
Step-by-step explanation:First one is 2
Answer:
See below
Step-by-step explanation:
1. 12
2. 15 [3*12-21 = 15]
3. 24 [3*15-21 = 24]
4. 51 [3*24 - 21 = 51]
Answer: x=6 y=6
Step-by-step explanation:

Since the right parts of the equation are equal, therefore the left parts of the equation are also equal:

Divide both parts of the equation by 2:

Answer:
4 times 3 is 12 and 12-17 is -5.
Step-by-step explanation: