Đáp án:

4 x 126 x 25

= ( 4 x 25 ) x 126

= 100 x 126

= 12600

a,

b,

a. 4 x 126 x 25

= (4 x 25) x 126

= 100 x 126

= 12600

b. (9 x 8 – 12 – 5 x 12) x ( 1 + 2 + 3 + 4 + 5)

= (72 – 12 – 60) x ( 1 + 2 + 3 + 4 + 5)

= 0 x ( 1 + 2 + 3 + 4 + 5)

= 0

a) 126 x 4 + 126 x 5 + 126

= 126 x 4 + 126 x 5 + 126 x 1

= 126 x ( 4 + 5 + 1 )

= 126 x 10

= 1260

b) 184 x 100 - 50 x 100

= ( 184 - 50 ) x 100

= 134 x 100

= 13400

126 x 4 + 126 x 5 + 126

= 126 x ( 4 + 5 + 1 )

= 126 x 10

= 1260

4*126*26

=504*26

=13104

=13104 nha

k mình đi

13104

Bài 1: Tính nhanh 

A, 13 x 126 + 37 x 126 - 49 x 126

= 126 x ( 13 + 49 - 49 )

= 126 x 1

= 126

B, ( 1 + 2 + 4 + 8+.....+ 512 ) x ( 101 x 102 - 101 x 101 - 50 - 51 )

= ( 1 + 2 + 4 + 8+.....+ 512 ) x ( 101 x ( 102 - 101 - 1))

= ( 1 + 2 + 4 + 8+.....+ 512 ) x ( 101 x 0)

= ( 1 + 2 + 4 + 8+.....+ 512 ) x 0

= 0

a)\(\left(-4\right).125.\left(-25\right).\left(-6\right).\left(-8\right)\)

\(=\left[\left(-4\right)\cdot\left(-25\right)\right]\cdot\left[125\cdot\left(-8\right)\right]\cdot\left(-6\right)\)

\(=100\cdot\left(-1000\right)\cdot\left(-6\right)\)

\(=600000\)

b) \(\left(-98\right)\cdot\left(1-126\right)-126\cdot98\)

\(=\left(-98\right)\cdot1-\left(-98\right)\cdot126-126\cdot98\)

\(=\left(-98\right)+98\cdot126-126\cdot98\)

\(=\left(-98\right)\)

Bài 1 : Tìm x

96-x.(x+1)=42

x(x+1)=138

2x+x=138

3x=138

x=46

Bài 2 : Tính Nhanh

a,19.27+47.81+19.20

=19.(27+20)+47.81

=19.47+47.81

=47(19+81)

=47.100

=4700

b,87.23+13.93+70.87

=87.(23+70)+13.93

=87.93+13.93

=93.(87+13)

=93.100

=9300

Bài 3: Tính Tổng

a,1+4+7+...+79

=(79+1).27:2

=80.27:2

=2160:2

=1080

b,15+17+19+21+...+151+153+155

=(155+15).71:2

=160.71:2

=11360:2

=5680

c,15+25+35+...+115

=130.11:2

=1430:2

=715

d,24+25+28+...+125+126

=150.103:2

=7725

 4 x 126 x6

=(4 x 125 + 4 x 1) x 6

=(500 +4)x6

=504 x 6

=3024 

4 x 126 x 6

= 504 x 6

= 3024

Chúc bạn học tốt

4 x 126 x 6

= 4 x 6 x 126

= 24 x 126 

= 3024