( x - 1 ) + ( x - 2 ) + ( x - 3 ) = 180
x - 1 + x - 2 + x - 3 = 180
3x - 1 - 2 - 3 = 180
3x - ( 1 + 2 + 3 ) = 180
3x - 6 = 180
3x = 180 + 6
3x = 186
x = 186 : 3
x = 62
(x-1)+(x-2)+(x-3)=180
x-1+x-2+x-3=180
3.x -1-2-3 = 180
3.x - 6 = 180
3.x = 180 + 6
3.x = 186
x = 62
(x-1)+(x-2)+(x-3)=180
=>3x-1-2-3=180
=>3x =180+3+2+1
=>3x =186
=>x =186:3
=>x =62
x - 1 ) + ( x - 2 ) + ( x - 3 ) = 180
x - 1 + x - 2 + x - 3 = 180
3x - 1 - 2 - 3 = 180
3x - 6 = 180
3x = 180 + 6
3x = 186
x = 186 ÷ 3
x = 62