Given:

He does mistake in the order of giving preference.
We should give preference in the order, division, multiplication, addition, subtraction.
But, he gave the first preferrence to the subtraction.
72-8=64
Next, he used division
64/2=32
Next he adds 32 with 8.
So, he gets 50.
But the actual simplification is,
Simplifying we get,

Hence, the correct value of the expression is 86.
3.75$ is the price of the item after the 95% price reduction.
Answer:
829839483847234
Step-by-step explanation:
9232478346374546
64364746
let the goldfish be x and the guppies be y
4x + 3y = 29...equ(1)
3x + 5y = 30...equ(2)
multiplying equation 1 by 5 and equation 2 by 3
20x + 15y = 145...equ(1)
9x + 15y = 90...equ(2)
subtracting equation 2 from 1
11x = 55
∴x = 5
substituting the value of x into equation
4(5) + 3y = 29
20 + 3y = 29
3y = 9
∴y =3