To find the value of \( x \) for the two adjacent angles \( x° \) and \( (x + 30)° \) that make up a \( 90° \) angle, we can set up the following equation:
\[ x + (x + 30) = 90 \]
Simplifying this equation:
\[ x + x + 30 = 90 \] \[ 2x + 30 = 90 \]
Now, subtract 30 from both sides:
\[ 2x = 60 \]
Next, divide by 2:
\[ x = 30 \]
Therefore, the value of \( x \) is \( 30° \).
The correct response is:
30