a/ 2145

b/-180

c/-130

d/0

tik nha mk nhanh nhất!

a , 100 + ( + 430 ) + 2145 + ( - 530 ) = 530 + 2145 - 530 = ( 530 - 530 ) + 2145 = 0 + 2145 = 2145

b , ( - 12 ) . 15 = - ( 12 . 15 ) = - 180

c , ( + 12 ) . 13 + 13.( - 22 ) = 13 . [ ( + 12 ) + ( - 22 ) ] = 13 . ( - 10 ) = - 130

d , { [ 14 : ( - 2 ) ] + 7 } : 2012 = { ( - 7 ) + 7 } : 2012 = 0 : 2012 = 0

a,100+(+430)+2145+(-530)=530+1615=2145

b,(-12).15=-180

c,(+12).13+13.(-22)=13(12+-22)=13.-10=-130

d,{[14 : (-2)]+7} : 2012={-7+7}:2012=0:2012=0

\(a,100+\left(+430\right)+2145+\left(-530\right)\)

\(=100+430+2145-530\)

\(=\left(100+2145\right)+\left(430-530\right)\)

\(=2245+\left(-100\right)\)

\(=2245-100\)

\(=2145\)

\(b,,\left(-12\right).15\)

\(=-180\)

\(c,\left(+12\right).13+13.\left(-22\right)\)

\(=13.\left[12-22\right]\)

\(=13.\left(-10\right)\)

\(=-130\)

\(d.\left\{\left[14:\left(-2\right)\right]+7\right\}:2012\)

\(=\left\{-7+7\right\}:2012\)

\(=0:2012\)

\(=0\)

Bấm máy tính đi má!

a) 100 + 430 + 2145 + (-530) = 100 + 430 + (-530) + 2145 = 530 + (-530) + 2145 = 0 + 2145 = 2145.

b) (-12) . 15 = -180.

c) (-12) . 13 + 13 . (-22) = 13 . (-12 + -22) = 13 . (-34) = (-442).

d) {[14 : (-2)] + 7} : 2012 = {(-7) + 7} : 2012 = 0 : 2012 = 0.

a.  100 + (+430) + 2145 + (–530)

= (100+2145) +[+430+(-530)]

=2245+(-100)

=2145

b.  (–12) .15 

= -180

c.  (+12).13 + 13.(–22)

= [+12 + (-22)].13

=-10.13

=-130

a) 100 + (+430) + 2145 + (-530)

= 100 + [ (+430) + (-530) ] + 2145

= 100 + (-100) +2145

= 0 + 2145 = 2145

b) (-12) . 15 . 8 . (-4)

= [ (-12) . 8 ] . [ 15. (-4)]

= (-96) . (-60) = 5760

c) (+12) . 13 + 13 . (-22)

= 13. [ (+12) + (-22) ]

= 13. (-10) = -130

d) { [14 : (-2)] + 7 } : 2012

= { [ (-7) + 7 } : 2012

= 0 : 2012 = 0

e) -23 . 63 + 23 . 21 - 58 . 23

= 23 . -63 + 23 . 21 - 58.23

= 23. ( -63 + 21 - 58 )

= 23 . -100 = -2300

Hok tốt !

a) 100 + (+430) + 2145 + (-530)

=100+[430+(-530)]+2145

=100+(-100)+2145

=0+2145

=2145

b) (-12) . 15 . 8 . (-4)

=(-12.8).[15.(-4)]

=-90.(-60)

=5760

c) (+12) . 13 + 13 . (-22)

=13.[12+(-22)]

=13.(-10)

=-130

d) { [14 : (-2)] + 7 } : 2012

={-7+7}:2012

=0:2012

=0

e) -23 . 63 + 23 . 21 - 58 . 23

=23.(-63)+23.21-58.23

=23.(-63+21-58)

=23.(-100)

=-2300

a) 100 +430 +2145+(-530)

=(100+2145) +[ 430+(-530)]

=2245 + (-100) =2145

b) (-12). 15 = -(12.15)= -180

c) 12.13 +13. (-22)= 13 [ 12+(-22)] =13 .(-10)= -(13.10)=-130

a) 100 + (+430) + 2145+ (-530)

= 100+ 430  + 2145 - 530

= 530 - 530 +2145

= 0 + 2145 = 2145

 b) (-12).15 = -10.15 -2.15 = -150 - 30 = -180

c) (+12).13 + 13.(-22)

= 13.   (12 - 22)

= 13. (-10)

= -130

d) {[14 : (-2)] + 7} : 2020

=     { - 7 + 7} : 2020

= 0 : 2020

=0

Học tốt

a) 100+430+2145+(-530)

=(100+2145)+[430+(-530)]

=2245+(-100)=2145

b) (-12).15=-180 (nếu muốn tính nhanh : (-12).15=(-3).4.15=(-3).60=-180)

c) 12.13+13.(-22)=13[12+(-22)]

                           =13.(-10)=-130

d) {[14:(-2)]+7}:2020

={(-7)+7}:2020

=0:2020=0

(+430) hay (-430)?

a) 100 + (+430) + 2145 + (-530) =530+2145+(-530)=2675+(-530)=2145

b) (-12).15=180

c) 12.13+13.(-22)=[12.(-22)] + 13 = -246+13=-251

d) {[14/(-2)]+7}/2020={[(-7)+7]}/2020=0/2020=0
Ko biết đúng hay sai :V

Tính dễ thì tự làm nha

2) Tìm x

a) Sửa đề:

\(\left|x\right|=10+-3\)

\(\left|x\right|=7\)

\(\Leftrightarrow x=\left\{\pm7\right\}\)

b)

\(\left|x\right|< 6\)

\(0\le\left|x\right|\)

\(\Leftrightarrow0\le\left|x\right|< 6\)

\(\left|x\right|\in\left\{0;1;2;3;4;5\right\}\)

\(x\in\left\{\pm1;\pm2;\pm3;\pm4;\pm5\right\}\)

Tổng là:

\(-5+-4+....+3+4+5\)

\(=\left(-5+5\right)+\left(-4+4\right)+\left(-3+3\right)+\left(-2+2\right)+\left(-1+1\right)+0=0\)

BÀI 1 : 

100+ 430+ 2145-530 = [( 100+430)-530] +2145

                                   = 530-530+2145

                                   = 0 + 2145 

                                   = 2145

-12.5=-60

12 .13+13 ,( -22) = 13.( -22+12)

                              = 13.(-10)

                              = -130

[ 14 : ( -2) +7] : 2012 = ( -7 +7) : 2012

                                   = 0 : 2012

                                    = 0

BÀI 2

3x - 5 = -7 -13

=> 3x- 5 = -20

=> 3x = -15

=> x = -5

IxI -10 = -3

=> I xI = 13

=> x = \(\pm\)13