The answer you is looking for is 6.
This is the equation this problem would make:
?^2-5*4-7/3+6=45
Since you know the answer, you can find a missing number by choosing the opposite symbol:
?/6+5/4+7*3-6=45
This is how you work backwards with this problem:
45-6= 39
39*3= 117
117+7= 124
124/4= 31
31+5= 36
36/6= 6
When you square root, you are taking the two numbers and multiplying then together. These numbers need to be the same, though. For example, 6*6=36, 6 squared=36.
If you put 6 where the ? is, your answer will be 45:
6^2-5*4-7/3+6=45
