Answer:
6r+7=13+7r
6r+7=7r+13
6r+7−7r=7r+13−7r
−r+7=13
−r+7−7=13−7
−r=6
= 
r=−6
Step-by-step explanation:
:) This is the answer
X is the number
sum means add
sum of half a number and 4 means
(x/2)+4
result is -16
(x/2)+4=-16
minus 4 both sides
x/2=-20
times 2 both sides
x=-40
the number is -40
???????????????????????????????????????????