Đáp án+Giải thích các bước giải:
`a) 230 + [ 2^4 + ( x - 5 ) ] = 315 . 2018`
`230 + [ 2^4 + ( x - 5 ) ] = 635670`
`2^4 + ( x - 5 ) = 635670 - 230 `
`2^4 + ( x - 5 ) = 635440`
`16 + ( x - 5 ) = 635440 `
`x - 5 = 635440 - 16 `
`x - 5 = 635424 `
`x = 635424 + 5 `
`x = 635429`
`b) 707 : ( 2^x - 5 ) + 74 = 4^2 - 3^2`
`707 : ( 2^x - 5 ) + 74 = 16 - 9 `
`707 : ( 2^x - 5 ) + 74 = 7 `
`( 2^x - 5 ) + 74 = 707 : 7 `
`( 2^x - 5 ) + 74 = 101 `
`2^x - 5 = 101 - 74 `
`2^x - 5 = 27 `
`2^x = 32 `
`2^x = 2^5 `
`x = 5 `
`c) [ ( 6x - 12 ) : 3] . 32 = 64 `
`( 6x - 12 ) : 3 = 64 : 32 `
`( 6x - 12 ) : 3 = 2 `
`( 6x - 12 ) = 2 . 3 `
`( 6x - 12 ) = 6 `
`6x = 6 + 12 `
`6x = 18 `
`x = 3`
`d) ( x : 7 + 15 ) . 23 = 391`
`x : 7 + 15 = 391 : 23 `
`x : 7 + 15 = 17 `
`x : 7 = 17 - 15 `
`x : 7 = 2 `
`x = 7 . 2`
`x = 14`
