Solution 1
Break the equation in 2…
17 + 47 = 64
Now you know whatever you add to 7 MUST equal 64.
The opposite of addition is subtraction so …. 64-7 = 57
Final answer 57
Solution 2
The answer is 57. 17 + 47 = 64 so 64 – 7 = 57
Solution 3
I’ll give it a shot…
17+47=7+57
Solution 4
It just wants you to find the other number.
47
+17
=64
So you have 64. 7 plus what makes 64?
64
- 7
=57
17+47=7+57
There you go. 😀
Solution 5
17+47=64
7+?=64
?=64-7
?=57
Solution 6
17+47=7+x
17+47-7=7-7+x
57=x