(+15)-(+5)= | (+15)+(-5)= | (+10) | |
(-15)-(-5)= | (-15)+(+5)= | (-10) | |
(+18)-(-2)= | (+18)+(+2)= | (+20) | |
(+15)-(-5)= | (+15)+(+5)= | (+20) | |
(+18)-(+2)= | (+18)+(-2)= | (+16) | |
(-18)-(-2)= | (-18)+(+2)= | (-16) | |
(-15)-(+5)= | (-15)+(-5)= | (-20) | |
(-18)-(+2)= | (-18)+(-2)= | (-20) |