Question

       Tính nhanh :

                    A =   18 x  [ 373737 / 424242  +   373737 / 565656  +  373737 / 727272 ]                 

 

Answer 1

\(A=18x\left(\frac{373737}{424242}+\frac{373737}{565656}+\frac{373737}{727272}\right)\)

    \(=18x\left(\frac{37x10101}{42x10101}+\frac{37x10101}{56x10101}+\frac{37x10101}{72x10101}\right)\)

     \(=18x\left(\frac{37}{42}+\frac{37}{56}+\frac{37}{72}\right)\)

       \(=18x\frac{37}{18}\)

        \(=37\)