You add 12...
r + (-12) = 19
r + (-12) + 12 = 19 + 12
r = 31
2
+6
Nothing because x = 3
10 which gives s a value of 24
32
+6
-64
2
+6
-21
Nothing because x = 3
11 So: x = 37
10 which gives s a value of 24
32
32
It is not an equation because there is no equal sign
96