I need some help understanding how to solve these problems, could I get some assistance?

4. [-/1 Points] DETAILS Write the partial fraction decomposition of the rational expression. Check your result algebraically. x2 + 4x + 3 x + X1. [-/1 Points] DETAILS Use any method to solve the system. (If there is no solution, enter NO SOLUTION. If the system is dependent enter a for x and enter y in terms of a.) -x + 3y = 29 10x + 3y = 7 (x, y ) = 2. [-/1 Points] DETAILS Solve the system of linear equations and check any solutions algebraically. (If there is no solution, enter NO SOLUTION. If the system is dependent, express x, y, and z in terms of the parameter a.) x+y+ z = 15