Answer
Find out the percent error in Annie's estimate .
To prove
Formula

As error = approx value - exact value
As given
Annie estimates that the height of a bookcase is 78.25 in.
The actual height is 75.50 in.
approx value = 78.25 in.
actual value = 75.50 in.
error = 78 .25 - 75 .50
= 2.75
put in the formula


Percentage error = 3.64 % (approx)
Therefore the Percentage error be 3.64 % (approx).
So b is the correct answer
49/63 and 48/63..........
Answer: The correct statements are
The GCF of the coefficients is correct.
The variable c is not common to all terms, so a power of c should not have been factored out.
David applied the distributive property.
Step-by-step explanation:
GCF = Greatest common factor
1) GCF of coefficients : (80,32,48)
80 = 2 × 2 × 2 × 2 × 5
32 = 2 × 2 × 2 × 2 × 2
48 = 2 × 2 × 2 × 2 × 3
GCF of coefficients : (80,32,48) is 16.
2) GCF of variables :(
)
= b × b × b × b
= b × b
=b × b × b × b
GCF of variables :(
) is 
3) GCF of
and c: c is not the GCF of the polynomial. The variable c is not common to all terms, so a power of c should not have been factored out.
4) 
David applied the distributive property.
Answer:
The answer should be 69°
Step-by-step explanation:
Each line is being cut by a transversal, that means that the degree on the other side of it, added with the given degree will add up to 180°
1. On the right, you need to find the interior angle where 160° is outside so you subtract 180° from 160° to find the angle inside. That gives you 20°
2. On the top left you have 131° so 180°-131°=49°
Next you add the angles you have and then subtract it from 180 to get the interior angle with n° outside.
3. 20°+49°=69°
4. 180°-69°=111°
Then you do the same thing as the beginning which would be n°+111°=180°
5. n°+111°=180°, that means n=69°
Hopefully that clears it up for you :)