How do you find the percent of a number? such as $28.80 dress is on sale for 40%. best explanation that i understand gets brainliest answer! : )

When can u say there is no solution for a system of linear inequalities? explain your answer and show with a system and graph

Me what is the value of x? showing work would be appreciated - ! : )

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).