How many subsets of four different numbers whose product is a square can be chosen from {1,2,3,4,5,6,7,8,9}?

Afarm that has 4 x 10^2 acres has 1.2 x 10^5 cattle. what is the average number of cattle per acre? write the answer in scientific notation. answere asap

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day