10 - 2x = -30
-2x = -40
2x = 40
x = 20
Answer:
This might be wrong but I think it is C
Step-by-step explanation:
Answer:
13 buttons
Step-by-step explanation:
The first step is to add the buttons received by the 6 students.
= 10 + 14 + 15 + 12 + 13 + 14
= 78 buttons
Therefore the number of buttons received by each students can be calculated as follows
= 78/6
= 13 buttons
Hence each student will receive 13 buttons