How do I do this help fast

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !