9 Test file number 16

  9.1 Problem number 1
  9.2 Problem number 10
  9.3 Problem number 18
  9.4 Problem number 19
  9.5 Problem number 25
  9.6 Problem number 26

Test folder name:

test_cases/1_Algebraic_functions/1.1_Binomial_products/1.1.1_Linear/16_1.1.1.5_P-x-a+b_x-^m-c+d_x-^n