Krishna
0

Step 1: Understand the question.  

            NOTE:  Right angle triangle ABC, right angle at C.

                          So, A and B are complimentary angles.


Step 2: Determine the unknown value

            NOTE: If \angle A \text{ and } \angle B  are the acute angles of

                          a  right triangle,  sin A = cos B

                    Plugging the known values

                            x + 0.1 = 2x - 0.4

                              2x - x = 0.1 + 0.4

                                    x = 0.5