a) \(37\times46+37\times51+111\)

\(=37\times46+37\times51+37\times3\)

\(=37\times\left(46+51+3\right)\)

\(=37\times100\)

\(=3700\)

b) \(35\times215-35\times210-175\)

\(=35\times215-35\times210-35\times5\)

\(=35\times\left(215-210-5\right)\)

\(=35\times0\)

\(=0\)

c) \(172\times47+86\times8-34\times4\)

\(=4\times\left(43\times47+86\times2-34\right)\)

\(=4\times\left(2021+172-34\right)\)

\(=4\times2159\)

\(=8636\)

d) \(48\times56+28\times104\)

\(=48\times56+56\times52\)

\(=56\times\left(48+52\right)\)

\(=56\times100\)

\(=5600\)

\(37\times46+37\times51+111\)

\(=37\times46+37\times51+37\times3\)

\(=37\times\left(46+51+3\right)\)

\(=37\times100\)

\(=3700\)

------------

\(172\times47+86\times8-34\times4\)

\(=172\times47+172\times4-34\times4\)

\(=172\times\left(47+4\right)-34\times4\)

\(=172\times51-34\times4\)

\(=172\times3\times17-17\times2\times4\)

\(=17\times\left(172\times3-2\times4\right)\)

\(=17\times\left(516-8\right)\)

\(=17\times508\)

\(=8636\)

------------

\(35\times215-35\times200-175\)

\(=35\times215-35\times200-35\times5\)

\(=35\times\left(215-200-5\right)\)

\(=35\times10\)

\(=350\)

------------

\(48\times56+28\times104\)

\(=48\times2\times28+28\times104\)

\(=28\times\left(48\times2+104\right)\)

\(=28\times200\)

\(=5600\)

88 800

261 304

không phải nhé

a )   ( -1/6 + 5/12 ) + 7/12

= -1/6 + ( 5/12 + 7/12 ) 

= -1/6 + 12/12

= -2/12 + 12/12 

=        -10/12

=        -5/6

9

Số dư: 9

Dư 9

1) \(\left(x-2\right)\left(x+4\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-2=0\\x+4=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-4\end{matrix}\right.\)

2) \(\left(x-2\right)\left(x+15\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-2=0\\x+15=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-15\end{matrix}\right.\)

3) \(\left(7-x\right)\left(x+19\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}7-x=0\\x+19=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=7\\x=-19\end{matrix}\right.\)

4) \(-5< x< 1\)

\(\Rightarrow x\in\left\{-1;-3;-2;-1;0\right\}\)

5) \(\left(x-3\right)\left(x-5\right)< 0\)

\(\Rightarrow\left[{}\begin{matrix}x-3>0\\x-5< 0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x>3\\x< 5\end{matrix}\right.\)

\(\Rightarrow3< x< 5\)

6) \(2x^2-3=29\)

\(\Rightarrow2x^2=29+3\)

\(\Rightarrow2x^2=32\)

\(\Rightarrow x^2=\dfrac{32}{2}\)

\(\Rightarrow x^2=16\)

\(\Rightarrow x^2=4^2\)

\(\Rightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

7) \(-6x-\left(-7\right)=25\)

\(\Rightarrow-6x+7=25\)

\(\Rightarrow-6x=25-7\)

\(\Rightarrow-6x=18\)

\(\Rightarrow x=\dfrac{18}{-6}\)

\(\Rightarrow x=-3\)

8) \(46-\left(x-11\right)=-48\)

\(\Rightarrow x-11=48+46\)

\(\Rightarrow x-11=94\)

\(\Rightarrow x=94+11\)

\(\Rightarrow x=105\)

1: (x-2)(x+4)=0

=>x-2=0 hoặc x+4=0

=>x=2 hoặc x=-4

2: (x-2)(x+15)=0

=>x-2=0 hoặc x+15=0

=>x=2 hoặc x=-15

3: (7-x)(x+19)=0

=>7-x=0 hoặc x+19=0

=>x=7 hoặc x=-19

4: -5<x<1

=>\(x\in\left\{-4;-3;-2;-1;0\right\}\)

5: (x-3)(x-5)<0

=>x-3>0 và x-5<0

=>3<x<5

6: 2x^2-3=29

=>2x^2=32

=>x^2=16

=>x=4 hoặc x=-4

7: -6x-(-7)=25

=>-6x=25-7=18

=>x=-3

8: 46-(x-11)=-48

=>x-11=46+48=94

=>x=94+11=105

( 81 x 70 - 2013 ) x ( 92 x 86 - 46 x 172 )

=( 5670 -2013 ) x ( 7912  - 7912 )

=3657 x 0

= 0

( 81 × 70 - 2013 ) × ( 92 × 86 - 46 × 172 )

= ( 5670 - 2013 ) × ( 7912 - 7912 )

= 3675 × 0 

= 0 

Chúc bạn học giỏi nha !!!

\(\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{1}{5}+\dfrac{32}{40}+\dfrac{48}{56}+\dfrac{14}{21}\\ =\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{1}{5}+\dfrac{4}{5}+\dfrac{6}{7}+\dfrac{2}{3}\\ =\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\left(\dfrac{1}{7}+\dfrac{6}{7}\right)+\left(\dfrac{1}{5}+\dfrac{4}{5}\right)\\ =1+1+1=3\)

Lời giải:

$\frac{1}{3}+\frac{1}{7}+\frac{1}{5}+\frac{32}{40}+\frac{48}{56}+\frac{14}{21}$

$=\frac{1}{3}+\frac{1}{7}+\frac{1}{5}+\frac{4}{5}+\frac{6}{7}+\frac{2}{3}$

$=(\frac{1}{3}+\frac{2}{3})+(\frac{1}{7}+\frac{6}{7})+(\frac{1}{5}+\frac{4}{5})$

$=\frac{3}{3}+\frac{7}{7}+\frac{5}{5}=1+1+1=3$

=(7/21 +14/21)+(8/56+48)+(8/40+32/40)

=1+1+1

=3

Tính nhanh:

a) 36.(65-79)+65|35-79|

=36.(-14) + 65.44

=-504 + 2860

=2356

b) 12.(34-86)+34.(86-12)+86.(12-34)-12.(34+86)

= 12.(-52) +34.74+86. (-22) - 12.120

=-624 + 2516 +(-1892) -1440

= 1892 + (-1892) -1440

=0- 1440

=-1440

a) 36 . (-14) + 65 . 44

= -504 + 2860

= 2356

Mình làm cho bạn câu cuối

...(x-3)+(x-2)+(x-1)+0+1+2+...+11=11

VP =11

=> VT=11

Để VT =11 cần có đủ cặp số đối đến (10)=> x-3=-10=> x=-7