`1`,
`a` , `64.25+25.36-47`
`=25.(64+36)-47`
`=25.100-47`
`=2500-47`
`=2453`
`b` , ( $2^{5}$ . `12` `+` `4.` $2^{5}$ ) : $2^{7}$
`=` $2^{5}$ . (`12+4`) : $2^{7}$
`=` $2^{5}$ . `16` : $2^{7}$
`=` $2^{5}$ . $2^{4}$ : $2^{7}$
`=` $2^{9}$ : $2^{7}$
`=` $2^{2}$
`c` , [`50-(17-54`:$3^{3}$)] . $2^{3}$ `+16`
`=` `[50-(17-54:27)]` . $2^{3}$ `+16`
`=` `[50-(17-2)]` . $2^{3}$ `+16`
`=` `[50-15]` . $2^{3}$ `+16`
`=` `35` . $2^{3}$ `+16`
`=` `35` . `8` + `16`
`=` `280+16`
`=` `296`
`2`,
`a` , Đúng
`b` , Sai
`→` $3^{2}$ . $4^{3}$ `=` `9.64` `=` 576`
`c` , Sai
→ $2^{3}$ `=` `8`
`d` , Sai
→ $2^{4}$ : $2^{4}$ `=` `1`
`e` , Đúng
`3` ,
`a` , `(x+74)-318=200`
`⇒` `x+74=200+318`
`⇒` `x+74=518`
`⇒` `x=518-74`
`⇒` `x=444`
`b` , (`12:3x`)$^{3}$ `=64`
`⇒` (`12:3x`)$^{3}$ `=` $4^{3}$
`⇒` `12:3x=4`
`⇒` `3x=12:4`
`⇒` `3x=3`
`⇒` `x=1`
`c` , `17x-x-82=1006`
`⇒` `16x-82=1006`
`⇒` `16x=1006+82`
`⇒` `16x=1088`
`⇒` `x=68`
`d` , $3^{x}$ `+1` `=` $6^{2}$ `-` ($3^{2}$ `-1`)
`⇒` $3^{x}$ `+1` `=` $6^{2}$ `-` `8`
`⇒` $3^{x}$ `+1` `=` `36-8`
`⇒` $3^{x}$ `+1` `=` `28`
`⇒` $3^{x}$ `=` `28-1`
`⇒` $3^{x}$ `=` `27`
`⇒` $3^{x}$ `=` $3^{3}$
`⇒` `x=3`
