public static void main ( String [ ] args ) {
  Scanner scanner = new Scanner ( System . in ) ;
  int t = scanner . nextInt ( ) ;
  for ( int i = 0 ;
  i < t ;
  i ++ ) {
    int x = scanner . nextInt ( ) , y = scanner . nextInt ( ) , a = scanner . nextInt ( ) , b = scanner . nextInt ( ) ;
    int distance = y - x , oneSecond = a + b ;
    System . out . println ( distance % oneSecond == 0 ? distance / oneSecond : - 1 ) ;
  }
}

public static void main ( String [ ] args ) { Scanner scanner = new Scanner ( System . in ) ; int t = scanner . nextInt ( ) ; for ( int i = 0 ; i < t ; i ++ ) { int x = scanner . nextInt ( ) , y = scanner . nextInt ( ) , a = scanner . nextInt ( ) , b = scanner . nextInt ( ) ; int distance = y - x , oneSecond = a + b ; System . out . println ( distance % oneSecond == 0 ? distance / oneSecond : - 1 ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (identifier))) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (identifier)))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (ternary_expression condition: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)) consequence: (binary_expression left: (identifier) right: (identifier)) alternative: (unary_expression operand: (decimal_integer_literal))))))))))