Ok so first I am assuming you ment 2 sevenths so 12 divided by 2 sevenths is 42. so the father is currently 42. so when she was 10 he was 40. since 10 is 4 times 40 that is the age we need. so 42 minus 40 is 2. therefore the answer is 2.
Step-by-step explanation:
the answer is in the above image
Answer:
Step 3
Step-by-step explanation:
Given

Required:
Determine the first step where she made mistake
Her Step 1:
--- This is correct because she solved the bracket first
Her Step 2:
--- This is correct because she solved 3^2 as 9
Her Step 3:
--- This is incorrect because 23 * 4 is not equivalent to 9 * 4
Hence, her first mistake is in step 3.
The correct expression would have been

Then

X+4x = 180
5x = 180
x =180/5
x = 36
answer
D. 36