Since the two adjacent angles are inside a 90° angle, their measures should add up to 90°.
So, (x+4) + (3x+2) = 90
Combining like terms, we get 4x + 6 = 90.
Subtracting 6 from both sides gives 4x = 84.
Finally, dividing both sides by 4 gives x = 21.
Therefore, x is equal to 21.