Note: Since the symbols for greatest integer function (GIF) and least integer function (LIF) are not given, I will be using the words GIF and LIF in the solution
GIF x means largest integer less than or equal to x, and LIF x means least integer greater than or equal to x.
We need to determine which expressions are equal
Option 1: GIF 4.9 and LIF 3.1
GIF 4.9 = 3
LIF 3.1 = 4
Hence GIF 4.9 ≠ LIF 3.1
Option 2: GIF 15.2 and GIF 14.8
GIF 15.2 = 15
GIF 14.8 = 14
Hence, GIF 15.2 ≠ GIF 14.8
Option 3: GIF -6 and LIF -6
GIF -6 = -6
LIF -6 = -6
Hence, GIF -6 = LIF -6
Option 4: LIF -3.2 and LIF -2.6
LIF -3.2 = -2
LIF -2.6 = -1
Hence, LIF -3.2 ≠ LIF -2.6
Hence, only in Option C the pair of expressions are equal.
I^5 + i^6 + i^7 + i^8
i^11 + i^15
i^26
therefore your answer is:
i^26
The first step is to name the equations to make the process of solving them easy.
The second step is to multiply each of the equations by the coefficient of the x term in the other equation. In this case, we will multiply equation (1) by 5 to get equation (3) and then multiply equation (2) by 6 to get equation (4).
The next step is to add equation equation(3) and (4) together to get equation (5) as shown below;
The next step is to take the value of y and substitute it into any of the equations above. For this solution, I pick equation (1). The work done to solve for x is shown below.;
The solution for this system of equations is 
I Am Going Ask My teacher. I just screenshot it.
