Answer:
18√5 or Decimal Form: 40.24922359…
Step-by-step explanation:
<span>3[4(23)-52+7(8+42)-16]</span>
<span>3 x (4 x 8 - 52
+ 7 x (8 + 42) - 16)</span>
<span>3 x (32 - 52
+ 7 x (8 + 42) - 16)</span>
<span>3 x (16 – 52
+ 7 x (8 + 42))</span>
<span>3 x (16 - 25 +
7 x (8 + 42))</span>
<span>3 x (-9 + 7 x
(8 + 42))</span>
3 x (-9 +7 x
(8 + 16))
3 x (-9 + 7 x
24)
3 x (-9 + 168)
3 x 159
477

We factor the denominators
Factor x^2 - 16
x^2 - 4^2
We use a^2 - b^2 = (a+b)(a-b)
so x^2 - 4^2 = (x+4)(x-4)
Replace it in the given equation

Excluded values are the values that makes the denominator 0
we have (x-4) and (x+4) in the denominator
We set the denominator =0 and solve for x
x-4 =0
Add 4 on both sides
x= 4
x+4=0
subtract 4 onboth side
so x= -4
Excluded values are x=-4 and x=4
b= 2 and 5
is your answer to the above question.