He will be making a right triangle with the legs being 24 x 45. The diagonal will be the hypotenuse of the triangle. To find the amount of fencing we need the perimeter of the triangle.
Use Pythagorean theorem to find the length of the hypotenuse.
a^2 + b^2 = c^2
24^2 + 45^2 = c^2
576 + 2025 = c^2
2601 = c^2
sqrt 2601 = c
c = 51
Adding the three lengths the total fencing needed is
51+24+45=120 meters
ANSWER

EXPLANATION
The given expression is

We regroup the numerical parts to get;

Now let us simplify the negative numbers.

We now subtract 19 from 42 to get;

We can't simplify further
Hence the simplest form is:

Answer:
the third
Step-by-step explanation:
your photo is not clear, and your explanations for your question is not clear also.
as we are tackling the substraction and the addition questions between matricxs.We could simply +/- every number correspondingly.
Answer:
C since y-x are being subtracted and there should be another subtraction but there isnt