It is in the form of  a 2 - b 2 a - b = a + b a - b a - b = a + b

Here a = 3.39   b = 2.61 

 = 3.39 + 2.61 = 6.

0.75 = 75/100 = 3/4

Converting each of the given fractions into decimal form, we get

2/3 = 0.66, 3/4 = 0.75, 4/5 = 0.8, 5/6 = 0.833 

Since 0.833>0.8>0.75>0.66 

So, 5/6 > 4/5 > 3/4 > 2/3 

Therefore,  Required Difference = 5/6 - 2/3 = 1/6

Let 138.009 + 341.981 - 146.305 = 123.6 + z

Then, z = (138.09+341.981) - (146.305+123.6)= 479.99 - 269.905 = 210.085

Here I converted the original fraction to a fraction with the denominator being 10, because decimals can be written in the tenths place.

$$\begin{gathered} Divide numerator and denominator with ' 2 ' \\ 1 5 x 2 2 \\ = 2 10 \\ = 0 . 2 \end{gathered}$$

Given 0.875 and 0.375

0.875 ::

After decimal point there are 3 digits 875

Now, mutiply and divide 0.875 with 1000

$$\begin{gathered} 0 . 875 x 1000 1000 = 875 1000 \\ Now , this can be reduced to fraction 7 8 \\ Therefore , 0 . 875 as fraction = 7 8 \end{gathered}$$

Similarly,

0.375 :: 

After decimal point there are 3 digits 375

Now, mutiply and divide 0.375 with 1000

$$\begin{gathered} 0 . 375 x 1000 1000 = 375 1000 \\ Now , this can be reduced to fraction 3 8 \\ Therefore , 0 . 375 as fraction = 3 8 \end{gathered}$$

0.46 = 46/100 = 23/50.

Sum of the numerator and denominator is 23 + 50 = 73

$$\begin{gathered} 6 . 46 = 6 + 0 . 46 \\ = 6 + 46 99 \\ 594 + 46 99 \\ = > 640 99 \end{gathered}$$

Given, 52416 / 312 = 168.

<=>  52416 / 168 = 312.

52.416 / 0.0168 = 524160 / 168 = 3120.

a^3 + b^3 = (a+ b) * (a^2 + b^2 - ab)

[ (10.3)^3 + (1)^3 ] / [(10.3)^2  + (1)^2 - (1 * 10.3)]

 => a + b = 10.3 + 1 = 11.3