`b ) 17 × 84 + 68 × 29`
`= 17 × 4 × 21 + 17 × 4 × 29`
`= 17 × 4 × ( 21 + 29 )`
`= 68 × 50`
`= 3400`
`g ) 3 × 12 × 25 + 9 × 20 × 4 + 92 × 2 × 9`
`= 3 × 3 × 4 × 25 + 3 × 3 × 20 × 4 + 46 × 2 × 2 × 9`
`= 9 × 4 × 25 + 9 × 20 × 4 + 46 × 4 × 9`
`= 9 × 100 + 9 × 80 + 184 × 9`
`= 9 × ( 100 + 80 + 184 )`
`= 9 × 364`
`= 3276`
`#dtkc`