10x-(3x7-3x2x)+18
10x-(21-3x2x)+18
10x-(21-6x)+18
10x-21+6x+18
16x-21+18
16x-3
5. After 6 hours, the concentration is halved. After 12 hours, it will be quartered. If the original concentration is 200 nmol, a quarter is 50 nmol.
14. The population doubles after 3 hours, and a day is 24 hours. That means that the original population should be multiplied by
, or
. 3 million times
is 3 * 256 million, or 768 million.
15. The concentration is halved every 8 hours and the original concentration is 100 nmol. So now, how many times do you halve 100 to get to 12.5?
100/2 = 50, 50/2 = 25, 25/2 = 12.5. That's three times. 3 * 8 is 24 hours, or 1 day.
Answer:
b 3x +7y =59
Step-by-step explanation:
x is water balloons at 3 each and y is t-shirts at 7$ each.
The ratio can be determined as,

Thus, the requried ratio is 7:12.