How to write a program that can solve these equation simultaneously ?

Assume that :W=50 lb, L=12ft, g=32.2 ft/s2, theta=35*pi/180 radians, mu_k=0.2; And the equation are:

Na-Fb= (W* ax /g); % equation # 1

Nb+Fa-W= (W* ay /g); % equation # 2

(((Na+Fb)*L*cos(theta))/(2)) + ((nb-Fa)*L*sin(theta))/(2)) =(( W*alpha*(L^2) )/ (12*g)); % equation # 3

mu_k*Na = Fa % equation # 4

mu_k*Nb = Fb % equation # 5

ax=(alpha*L*cos(theta))/(2); % to calculate ax; % equation # 6

ay=(alpha*L*sin(theta))/(2); % to calculate ax; % equation # 7