\(58.\left(3\dfrac{1}{29}-2\dfrac{1}{58}\right)\)
\(=58.\left(\dfrac{88}{29}-\dfrac{117}{58}\right)\)
\(=58.\dfrac{88}{29}-58.\dfrac{117}{58}\)
\(=176-117\)
\(=59\)
\(58\left(3\dfrac{1}{29}-2\dfrac{1}{58}\right)\)
\(=58\left(3+\dfrac{1}{29}-2-\dfrac{1}{58}\right)\)
\(=58\left(1+\dfrac{1}{29}-\dfrac{1}{58}\right)=58\left(1+\dfrac{1}{58}\right)\)
\(=58+1=59\)