19. (X+5)-3
20. 2a
21.3b
22. 5y-5
23. 1/2n-15
Answer:
45
Step-by-step explanation:
To find the number you just add 6 to 39 which gets you 45.
Answer 3x3.4
Step-by-step explanation:
Answer:
0
Step-by-step explanation:
2 + 2 = 4 and then 4 - 4 = 0

this is the answer, its pretty simple. I'm not sure the mathematical procedures but if you plug in 7 you get 49. Then all you got to do is subtract by 7, because the question states the number is the same. So basically,