Tickets for a play at the community theater cost $8 for children and $20 for adults. A total of 300 tickets have been sold for 3,900. How many children’s tickets have been sold?

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

Solve the equation x/4 - 5= -8 -27 -12 -7 12