Question

Bài 1.Thực hiện phép tính:

a) (-7) + (-5)

b) 47– (12– 29)

c) (-12).7.(-2)

d) (-9) + (-15) + (-33)

e) (-15).6

f) 5.( -9) + 4.9

Answer 1

a, \(\left(-7\right)+\left(-5\right)=-\left(7+5\right)=-12\)

b, \(47-\left(12-29\right)=47-\left(-17\right)=64\)

c, \(\left(-12\right).7.\left(-2\right)=24.7=168\)

d, \(\left(-9\right)+\left(-15\right)+\left(-33\right)=-57\)

e, \(\left(-15\right).6=-90\)

f, \(5.\left(-9\right)+4.9=\left(-5\right).9+4.9=9.\left[\left(-5\right)+4\right]=9.\left(-1\right)=-9\)

Answer 2

a)(-7)+(-5)=-12

b)47-(12-29) c)(-12).7.(-2)

=47-(-17) =-84.(-2)

= 64 =168

d)(-9)+(-15)+(-33) e) (-15).6 5.(-9)+4.9

=-24+(-33) =-90 =-45+36

=-57 =9