Answer:
Im going to guess that this is a true or false question so..
True :)
It would be written as a fraction to make the exponent negative put it over one : 1/7^4
If BD is congruent to BC, that means that the sides are equal, so their angles are too.
6x-9 = 3x+24
3x = 33
x = 33/3
x = 11
Angle BCD:
6×11-9 = 66-9 =57°
Angle BDC:
3×11+24 = 33+24 = 57°
Angle B:
x = 180° - 2×57°
x = 66°
The value of the expression
is 
<h3>How to evaluate the sum?</h3>
The attachment represents the proper format of the question
The summation expression is given as:

Expand the radicands

Evaluate the square roots

Add the like terms

Hence, the value of the expression
is 
Read more about expressions at:
brainly.com/question/723406
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