Answer:
[81 is the missing number.]
Step-by-step explanation:
7+x=88
Let us substitute the mixing number as x.
To find a variable we must ISOLATE it.
To isolate in this situation, we must remove the 7.
We must subtract 7 from both sides, to isolate x. like this-
7-7+x=88-7
This results in,
x=81
So this missing number or (x) is equal to 81
