There's a rectangle with the perimeter of 42. The side lengths are x+4 and 2(x)-7,what are the correct side lights ?

Question

4 different answers ,they all add to 42. Tried to find x to find perimeter and failed to get  answer.

Answer 1

2(x + 4) + 2(2x - 7) = 42               divide both sides by 2

x + 4 + 2x - 7 = 21                        combine like terms

3x - 3 = 21                                     add three to both sides

3x = 24                                          divide both sides by 3

x = 8