2x + 5x + 1= 15
7x =15-1
7x=14;
x=14 :7=2
.
6x = 7x – 15
6x - 7x=-15;
-x=-15
x=15
.
6x + 3y – 2x = 3y – 16
4x +3y =3y -16
4x +3y -3y=-16
4x =-16
x =-16 : 4=-4
.
|x + 2| = 0
<=> \(\left[ \begin{array}{l}x+2=0\\-(x+2)=0\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=-2\\-x-2=0\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=-2\\-x=2\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=-2\\x=-2\end{array} \right.\)
=> x=-2
.
156 – (x + 61) = 82
156 -x -61 =82
(156-61)-x=82
95-x=82
-x=82-95
-x=-13
x=13