Tan(-163) =
tan 17°
-tan 117°
tan 17°
tan 117

How to do this , and can some one explain

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?

Which of these statements is correct? the system of linear equations 6x - 5y = 8 and 12x - 10y = 16 has no solution. the system of linear equations 7x + 2y = 6 and 14x + 4y = 16 has an infinite number of solutions. the system of linear equations 8x - 3y = 10 and 16x - 6y = 22 has no solution. the system of linear equations 9x + 6y = 14 and 18x + 12y = 26 has an infinite number of solutions.