Please assist by showing how to solution is obtained.
12. The weekly demand model for a new toy is given by:
N = -5p + 80
The weekly supply model for the same toy is:
N = 3p + 40
For the models p is the price of the toy and N is the number of toys sold or supplied. Find the price at which supply and demand are equal.
13. A charity sells tickets for a fundraising dinner. Each adult's ticket costs $10 and each child's ticket costs $5. A total $1050 was raised by selling 130 tickets. How many adults tickets were sold? How many children's tickets were sold?
14. The perimeter of a rectangular room is 120 feet. The sum of four times the width and three times the length is 204 feet. Find the length and the width.