What is the determinant of the coefficient matrix of the system?

Abus ride for a senior citizen cost $1.25. a monthly pass costs $35. write and inequality that represents the number of times a senior citizen must ride the bus for the monthly pass to be a better deal.

Aplane is taking off from bangladesh headed to new york city. at the same time, a plane from new york city is headed to bangladesh is also taking off. the plane bound to new york city is traveling at 600 mph, while the plane traveling to bangladesh is traveling at 400 mph. how far from new york city will the two planes meet if the distance between new york city and bangladesh is 8,000 miles?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.