First you divide the smaller number by the larger number, to see how many of that number goes into the other:
45/50 = 0.9
The you times it by 100 to get the percentage:
0.9*100 = 90%
Hope this helps! :)
Distribute the 6 to 2x - 11
12x - 66 + 15 = 21
12x = 72
x = 6
A good rule is to change 10 to 15 percent of the water each week. If your tank is heavily stocked, bump that up to 20 percent each week. A lightly stocked aquarium can maybe get by for two to four weeks, but this should be the maximum length of time between water changes.
It is 2x+8!!!!!!! I’m pretty sure
