A sum of money at simple interest doubles itself in 10 years. Find the rate percent per annum​

The school that imani goes to is selling tickets to the annual dance competition. on the first day of the ticket sales the school sold 7 adult tickets and 5 child tickets for a total of $96. the school took in $40 on the second day by seling 3 adult tickets . find the price of an adult ticket and the price of a child ticket. solve by using substitution elimination college prep algebra math heres the 2 equations i came up with 7x+5y=96 and 3x+2y= -40 show all workiv be stuck on this.

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x