Of the four given equations, the first three are solved on the basis of a certain system, where the function of the shape " " remains the same. Find the correct answer for the unsolved fourth equation on the same basis.

Correct option is C

in option (a )we put value of  a=7 and b=3 

​$$\frac{(ab + b)}{a}$$=​$$\frac{(21+ 3)}{7}$$ ≠8

in option (b )we put value of  a=7 and b=3 

​$$\frac{(a - b)}{ab}$$=​$$\frac{(7 - 3)}{21}$$  ≠8

in option (c )we put value of  a=7 and b=3 

​$$\frac{(ab+b)}{b}$$=​$$\frac{(21+3)}{3}$$ =$$\frac{24}{3}$$=8​

in option (d )we put value of  a=7 and b=3 

​$$\frac{ab}{a+b}$$=$$\frac{21}{10}$$ ≠8

so only option c gives answer correctly.

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