Respuesta :
Answer: I belive that the answer to part A is 4x + 8.
7x - 3x = 4x. 13 - 5 = 8. Combine those and you get 4x + 8.
Part B is X= 11.
Step-by-step explanation: For Part B, the equation would be 7x + 13 = 90
                                               - 13  - 13
                                            7x = 77
                                           __   __
                                            7    7
        Â
                                            x = 11 Â