Răspuns :
3×{6×[5×(2x+34)-248]+12}=252
6×[5×(2x+34)-248]+12=252:3
6×[5×(2x+34)-248]+12=84
6×[5×(2x+34)-248]=84-12
6×[5×(2x+34)-248]=72
5×(2x+34)-248=72:6
5×(2x+34)-248=12
5×(2x+34)=12+248
5×(2x+34)=260
2x+34=260:5
2x+34=52
2x=52-34
2x=18
x=18:2
x=9
3*{6*[5*(2x+34)-248]+12}=252
6*[5*(2x+34)-248]+12=252:3
6*[5*(2x+34)-248]+12=84
6*[5*(2x+34)-248]=84-12
6*[5*(2x+34)-248]=72
5*(2x+34)-248=72:6
5*(2x+34)-248=12
5*(2x+34)=12+248
5*(2x+34)=260
2x+34=260:5
2x+34=52
2x=52-34
2x=18
x=18:2