Question

3•{5•[7•(4x-10)-13]-3}+1=7 dau coroana

Answer 1

3•{5•[4x-10)-13]-3}+1=7|-1
3•[5•(4x-10-13)-3]=6|:3
5•(4x-10-13-3)=2|:5
4x-10-13-3=2/5(Acum faci factor comun si amplifici cu 5) |•5
20x-50-65-15=10|+15
20x-50-65=25|+65
20x-50=90|+50
20x=140|:20
x=7