a) -8; -9; -10; ...; 5; 6; 7

b)

1) 700

2) -1201

a) -7 < 0,1,2,3,4,5,6,7<8

b) 

1) 631  + [ 587 - (287+231)]                                

= 631 + [ 587 - 518 ] 

= 631 + 69

=700                                              

2)  (-524) – [(476 + 245) - 45]

= (-524) – 476 – 245 + 45

= (-524) + (– 476) + (– 245) + 45

= (-1000) + (-200)

= -1200.

= 631 + 69                                                   

= 700

a) Tìm các số nguyên x thỏa mãn: \(-7< x< 8.\)

\(x=\left\{-6;-5;-4;-3;-2;-1;0;1;2;3;4;5;6;7\right\}.\)

b)  Tính nhanh các tổng:

1)  \(631+\left[587-\left(287+231\right)\right]=631+587-287-231=\left(631-231\right)+\left(587-287\right)=400+300=700.\)

2)  \(\left(-524\right)-\left[\left(476+246\right)-45\right]=\left(-524-246\right)+\left(-476+45\right)=-1201.\)

a)=234(1257-257)

=234.1000

=234000

b)=524(1327-327)

=524.1000

=524000

c)=325(1574-325-24)

=325.1225

=398125

d)=175(1274-273-1)

=175.1000

=175000

234x (1257-257)= 234 x 1000 = 234000

1327 x 524 - 524 x 327 = 524 x (1327 - 327 ) = 524 x 1000 = 524000

325x1574 - 325 x 325 -325 x24 =325 x(1574 - 325 - 24 )= 325 x 1225 =398125

175 x 1274 - 175 x273 -175 = 175 x (1274 - 273 -1) = 175 x 1000= 175000

                 kkk mk nha bạn !!!!!!!!

a)234 x 1257 - 234 x257

= 234 x (1257 - 257)

= 234 x 1000

= 234000

b)1327 x 524 - 524  x327

= 524 x (1327 - 327)

=524 x 1000

=524000

c)325 x 1574 - 325 x325 - 325 x24

= 325 x (1574 -325 - 24)

=325 x 1225

=325 x 1000+325 x 100 +325 x125

=325000+32500+40625

=390125

d)175 x 1274 - 175 x 273 - 175

=175 x (1274-273-1)

=175 x 1000

=175000

156-56x=24x-156

=>156+156=24x+56x

80x=312

x=3,9

VT=-4(14x-39)

VP=12(2x-13)

=>-4(14x-39)=12(2x-13)

=>-80x=-312

=>x=\(\frac{39}{10}\)

156-56x=24x-156

=>156=24x-156+56x

=>156=80x-156

=>156+156=80x

=>312=80x

=>312:80=x

=>x=3,9

1: x = 371

2: x = 412

3: x = 725

4: x = 536

1) x= 371

2) x= 412

3)x= 725

4) X= 536

 x : 5 = 156

           x = 156 x 5

           x = 780

 (x+1).x=156 => x . x + x . 1 = 156

=> x^2 + x = 156

x^2 + x = x^3 = 156 . 

=> x = 12

=> x . x + x . 1 = 156

=> x² + x = 156

Mà 156 = 12² + 12

=> x = 12

Đáp án cần chọn là: D