This is how you solve it; but first of all convert the percent into a decimal;55%= 0.55
0.55x = 164 (divide by 0.55 on both sides)
x = 164/0.55
x = 298.18 (rounded to the nearest hundredth)
so 164 is 55% of 298.18(rounded)
The fabric costs $8.95 per yard
In the old aquarium, 3 tablespoons of salt were used for 20 gallons. That's a conversion ratio of

That is, for every gallon of water in the aquarium, there was 0.15 tbsp of salt. So a 50 gallon aquarium, Ill should add

to maintain the salinity.
4^-3
You first need to make the exponent positive. To do this put it in a fraction.
1/4^3
Now solve the exponent.
4 * 4 * 4 =
^
16*4 = 64
1/64 is your answer