The answer is B. x = 29
Here's how I solved for x.
Step 1: Simplify [tex] x + -21 [/tex] to [tex] x = 21 [/tex]. Which leaves us with [tex] x - 21 = 8 [/tex]
Step 2: Add 21 to both sides. Which leaves us with [tex] x = 8 + 21 [/tex]
Step 3: Add [tex] 8 + 21 [/tex] to get your answer: x = 29
