Browse · harp Print → jmc prealgebra junior Problem 1−2+3−4+5−6+7−8+910−9+8−7+6−5+4−3+2−1= (A) −1 (B) 1 (C) 5 (D) 9 Solution — click to reveal 1−2+3−4+5−6+7−8+910−9+8−7+6−5+4−3+2−1=1+(−2+3)+(−4+5)+(−6+7)+(−8+9)(10−9)+(8−7)+(6−5)+(4−3)+(2−1)=1+1+1+1+11+1+1+1+1=1→1. Final answer B ← Previous problem Next problem →