Question

399x45 + 55 x 399/ 1995 x 1996 - 1991 x 1995 

Answer 1

`(399 xx 45 + 55 xx 399)/(1995xx1996-1991xx1995)`

`= (399xx(45+55))/(1995xx(1996-1991))`.

`= (399xx100)/(1995xx5)`

`= (399 xx 5 xx 5 xx 4)/(1995 xx 5)`

`= 4`.

Answer 2

\(\dfrac{399\times45+55\times399}{1995\times1996-1991\times1995}\)

\(=\dfrac{399\times\left(45+55\right)}{1995\times\left(1996-1991\right)}\)

\(=\dfrac{399\times100}{1995\times5}\)

\(=\dfrac{399\times5\times5\times4}{399\times5\times5}\)

\(=\dfrac{1\times1\times1\times4}{1\times1\times1}\)

\(=4\)