You did everything correctly! I did it myself...all of your subtraction is correct, then I added the answers together and I got 51. Where you trying to get another answer?
Answer:

Step-by-step explanation:
A = 5
B = 1
h = 2
k = -2
Use ABhk
Set up a proportion: 3/10= x/80. Then if you multiply 10 by 8, you get 80 on both sides, But, If you do it to the top, you also have to do it to the bottom, so the anser is 3 x 8 , or 24.
Step-by-step explanation:
Here, The work of a student to solve the equation :

The steps for calculating the value of x are :
Step 1: 4(2x − 4) = 8 + 2x + 8
Step 2: 6x − 8 = 16 + 2x
Step 3: 6x − 2x = 16 + 8
Step 4: 4x = 24
Step 5: x = 6
Step 2 is incorrect, as the student instead of multiplying, adds the number as :
4(2x − 4) = 8 + 2x + 8
Here, the correct step is :
8x − 16 = 16 + 2x
6 x = 32
x = 5.33
So, the error is in STEP 2 and the correct option is (b).
Answer:
it would be -5 im not sure why theres 4