Answer:
Here is the full proof:
AC bisects ∠BCD Given
∠CAB ≅ ∠CAD Definition of angle bisector
DC ⊥ AD Given
∠ADC = 90° Definition of perpendicular lines
BC ⊥ AB Given
∠ABC = 90° Definition of perpendicular lines
∠ADC ≅ ∠ABC Right angles are congruent
AC = AC Reflexive property
ΔCAB ≅ ΔCAD SAA
BC = DC CPCTC
-x + -x-1 + -x-2 = -204
-3x=-201
x=-67
-67-68-69=-204
You want to do to one side the same thing you do to the other side.
In order to get the n by itself you divide the 25n by 25. But in order to not change the answer you need to do the same to the 70.

so n=

which can be reduced to

so n=

the first number must be between 1 and 10 (here is 3.3)
the power (here is 5) is an integer exponent of 10 that indicates how many places the decimal point must be moved to make equation true
Greetings,
n00nst00p :)