Question

tính tổng:

Answer 1

c) -287 + 499 + (-499) + 285 = -2

d) 3 + (-5) + 7 + (-9) + 11 + (-13) + 15 + (-17) = -8

Answer 2

c) = -2

d) = -8

Answer 3

`c)-287 + 499 + (-499) + 285 = [499 + (-499)] + [(-287) + 285] = 0 + -2=-2`

`d)3+(-5)+7+(-9)+11+(-13)+15+(-17)=(3+7)+[(-5)+15] + [(-9)+11] + [(-13) + (-17)]=10 + 10 + 2 + (-30) = 20+2+(-30)=22+(-30)=-8`

Answer 4

\(\left(-287\right)+499+\left(-499\right)+285=\left(-287+285\right)+\left(499+-499\right)=-2+0=-2\)

\(3+\left(-5\right)+7+\left(-9\right)+11+\left(-13\right)+15+\left(-17\right)=\left(3+-13\right)+\left(-5+15\right)+\left(7+-17\right)+\left(-9+11\right)=-10+10+-10+2=-8\)