The amounts of industrial waste generated in a region during two years were 31,900,000 tons and 53,400,000 tons. what was the total industrial waste generated over these two years in the region, expressed in scientific notation?

Country carpets charges $22 per square yard for carpeting, and an additional installation fee of $100. city carpets charges $25 per square yard for the same carpeting, and an additional installation fee of $70

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.

For the equations below which statement is true ?