You can buy 5 bottles because $4 times 5 equals $20. I hope this helps :)
Answer:
Step-by-step explanation:
2
x
2
+
8
−
4
x
+
3
x
−
6
x
2
+
7
Subtract
6
x
2
from
2
x
2
.
−
4
x
2
+
8
−
4
x
+
3
x
+
7
Add
8
and
7
.
−
4
x
2
−
4
x
+
3
x
+
15
Add
−
4
x
and
3
x
.
−
4
x
2
−
x
+
15
Answer:

Step-by-step explanation:
The half life is the amount of time it takes a substance to decay to half of its original amount.
Since the radioactive substance has a half life of 1000 years, there will be half of it left after 1000 years.
So, the fraction that will be left after 1000 years is 