To represent the problem mathematically, we need to define a variable for the height that Cheyenne's brother climbs. Let's let \( x \) represent the height that Cheyenne's brother climbs.
According to the problem, Cheyenne climbs 468 feet, which is 129 feet more than what her brother climbs. We can set up the equation as follows:
\[ 468 = x + 129 \]
This can be rearranged to fit one of the given response options. The correct response from the options would be:
\[ x + 129 = 468 \]
So the answer is:
x + 129 = 468