`a,`
`x*3+7=16`
`=>3x = 16 - 7`
`=> 3x = 9`
`=> x = 9 \div 3`
`=> x = 3`
Vậy, `x = 3`
`b,`
` x- 152 \div 2 = 46?`
`=> x - 76 = 46`
`=> x = 46 + 76`
`=> x = 122`
Vậy, `x = 122.`
`c,`
` 74-2*(x+3)=34`
`=> 2(x + 3) = 74 - 34`
`=> 2(x+2) = 40`
`=> x + 2 = 40 \div 2`
`=> x + 2 = 20`
`=> x = 20 - 2`
`=> x = 18`
Vậy, `x = 18.`