15
11.. 7+4=11 and 15-4=11
10 is the number halfway between -5 and 15.It is: 5
Halfway between 10 and 15 is (10 + 15) ÷ 2 = 121/2
15
15
11.. 7+4=11 and 15-4=11
It is 15
10 is the number halfway between -5 and 15.It is: 5
26
The halfway number is (15 + 129) /2 = 144/2 = 72
Halfway between 10 and 15 is (10 + 15) ÷ 2 = 121/2
15
15
It is: 15
57
26