Can you help me out?

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)

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.

Choose the right classification of 5x + 3x^4 - 7x^3 + 10 by number terms and he degree 1. third degree polynomial 2. fourth degree polynomial 3. sixth degree polynomial 4. first degree binomial