30/2 = 15
15 x 5 = 75
The number is 75.
(10n-5)/(5)= 2n-1
just divide
10/5 = 2 and -5/5 =-1
and you get the answer
2n-1= 2n-1
Answer:
Step-by-step explanation:
let present age of
Dylan=x
Renee=y
x+y=57
9 years ago
x-9=2(y-9)=2y-18
x=2y-18+9=2y-9
so 2y-9+y=57
3y=57+9=66
y=66/3=22
x+22=57
x=57-22=35
Dylan's present age=35 years
30 x 28= 840
It's would beat 840 times in half an hour.