2006-11-29 14:17:17 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
9...two negative make a plus.
2006-11-29 14:26:08 · answer #1 · answered by wooliebear07 3 · 0⤊ 0⤋
-12 + 21 = 9.
2006-11-29 14:31:07 · answer #2 · answered by steiner1745 7 · 0⤊ 0⤋
-12-(-21) = -12+21
=9
2006-11-29 14:37:14 · answer #3 · answered by sanjeewa 4 · 0⤊ 0⤋
9
2006-11-29 14:28:25 · answer #4 · answered by zzzzz 2 · 0⤊ 0⤋
9
Double negative becomes positive.
-12+21
Reverse.
21-12=9
2006-11-29 14:26:09 · answer #5 · answered by reversedacurse90 3 · 0⤊ 0⤋
" - (-21) " means multiply -21 by -1
so -1 x -21 = 21
Now you have -12 + 21 = 9
2006-11-29 14:26:05 · answer #6 · answered by Mahwy1 1 · 0⤊ 1⤋
9
since its - ( - 21) .....that turns into + 21.... so its -12 + 21... which is 9
2006-11-29 14:27:10 · answer #7 · answered by Horsebackrider 2 · 0⤊ 0⤋