Answer:
13
Step-by-step explanation:
In order to make the equation true, the blank must be filled with a number that gives 78 when it is multiplied by 6. The missing number can be found as ...
78/6 = 13
The value that makes the equation true is 13.
42 +78 = 6(7 +13)
_____
Simplifying gives ...
120 = 6(20)
