Question

tính nhanh các tổng sau

a, (2736-75)-2736

b, (-2002)-(57-2002)

Answer 1

a, (2736-75)-2736

=2736-75-2736

=(2736-2736)-75

=0-75

=-75

b, (-2002)-(57-2002)

=[(-2002)-(-2002)]-57

=0-57

=-57

ai k mk rui mk k lai

Answer 2

a) (2736 - 75) - 2736

= 2736 - 75 - 2736

= (2736 - 2736) - 75

= 0 - 75

= -75

b) (-2002) - (57 - 2002)

= -2002 - 57 + 2002

= (-2002 + 2002) - 57

= 0 - 57

= -57

Answer 3

a)(2736-2736)-72

=0-72

=-72

b)(-2002)-(57-2002)

=(-2002+2002)-57

=0-57

=-57

Answer 4

tìm x biết 

x.(x+2)=0

|x-5|=7