B= (-23)(53+18) + 53(18+23)

B= (-23).53 + (-23).18 + 53.18 + 53.23

B= 53(23-23) + 18(53-23)

B= 0 + 18.30 

B= 540

B = -23 ( 53 + 18 ) + 53 ( 18 + 23 )

= -23 . 53 - 23 . 18 + 53 . 18 + 53 . 23

= ( -23 . 53 + 53 . 23 ) + ( - 23 . 18 + 53 . 18 )

= 0 + 18 ( -23 + 53 )

= 18 . 30 = 540

Vậy B = 540.

B=-23.53+(-23.18)+53.18+53.23

B=-1219 - 414 +954 +1219

B=-414 + 954 

B=540

a) \(\text{13 x 58 x 4 + 32 x 26 x 2 + 52 x 10 }\)

\(\text{=(13 x 4 ) x 58 + 32 x 13 x 2 x 2 + 13 x 4 x 10}\)

\(\text{= ( 13 x 4 ) x 58 + 32 x ( 13 x 2 x 2 ) + ( 13 x 4 ) x 10 }\)

\(\text{= 52 x 58 + 32 x 52 + 52 x 10}\)

\(\text{=52 x ( 58 + 32 + 10 )}\)

\(\text{=52 x 100 = 5200}\)

b) \(\text{14 x 35 x 5 + 10 x 25 x 7 + 20 x 70 x 2}\)

\(\text{= ( 14 x 5 ) x 35 + (10 x 7 ) x 25 + 20 x 70 x 2 }\)

\(\text{= 70 x 35 + 70 x 25 + 20 x 2 x 70 }\)

\(\text{= 70 x ( 35 + 25 + 40 )}\)

\(\text{= 70 x 100 = 7000 }\)

e) \(\text{5.3.37.4+5.24.21+21.5.12}\)

\(\text{= 5.(3.37.4+24.21+21.12)}\)

\(\text{= 5.1200}\)

\(=6000\)

a) \(13.58.4+32.26.2+52.10\)

\(=52.58+32.52+52.10\)

\(=52.\left(58+32+10\right)\)

\(=52.100=5200\)

b) \(14.35.5+10.25.7+20.70\)

\(=7.5.35.2+10.7.25+20.70\)

\(=35.70+70.25+20.70\)

\(=70\left(35+25+20\right)\)

\(=70.80=5600\)

c) \(...=15\left(27+18+6+23+12\right)\)

\(=15\left(27+23+18+12+6\right)\)

\(=15\left(50+30+6\right)=15.86=1290\)

d) \(...=53\left(51+4+49+96+1\right)\)

\(=53\left(51+49+4+96+1\right)\)

\(=53\left(100+100+1\right)=53.201=10653\)

e) \(15.37.4+120.21+21.5.12\)

\(=15.4.37+60.2.21+21.60\)

\(=60.37+60.42+21.60\)

\(=60.\left(37+42+21\right)=60.100=6000\)

Tải PHOTOMATH bạn nhé

a, 39*49-39*17    

= 39 (49 - 17)

= 39 * 32

= 1248

b,12*53+53*172-53*84

= 53 (12 + 172 -84)

= 53 * 100

= 5300

c,17+18+19+99  

= 17 + 17 +1 + 17 +2 + 99

= 3 * 17 + (1+ 99) + 2

= 151 +2

= 153

d, 23+25+49

= 48 + 49

= 97

e,46-45+44-43

= (46 + 44) + (-45 -43)

= 88 + (-88)

= 0

Tính hợp lí

a,15.(27+ 18 +6 ) + 15.( 23 +12)

  = 15(27+18+6+23+12)

  = 15.86

  = 1290

b,24.(15 + 49 ) + 12. ( 50 + 42 )

=12.2(15+49)+12.(50+42)

= 12(30+98)+12(50+42)

=12(30+98+50+42)

=12.220

= 2640

c,53.(51+4)+53.(49+96) +53

=53(51+4)+53(49+96)+53.1

=53(51+4+49+96+1)

=53.201

=10653

d,42.( 15 +96) +6.(25 +4).7  

=42(15+96)+42(25+4)

=42(15+96+25+4)

=42.140

=5880

tick đúng cho mk nha pikachu

20-2.(x+14)=16

Tính hợp lí:

\(a)\)\(15.\left(27+18+6\right)+15.\left(23+12\right)\)

\(=\)\(15.51+15.35\)

\(=\)\(15.\left(51+35\right)\)

\(=\)\(15.86\)

\(=\)\(1290\)

\(b)\)\(24.\left(15+49\right)+12.\left(50+42\right)\)

\(=\)\(24.64+12.92\)

\(=\)\(1536+1104\)

\(=\)\(2640\)

\(c)\)\(53.\left(51+4\right)+53.\left(49+96\right)+53\)

\(=\)\(53.55+53.145+53\)

\(=\)\(53.\left(145+55+1\right)\)

\(=\)\(53.201\)

\(=\)\(10653\)

\(d)\)\(42.\left(15+96\right)+6.\left(25+4\right).7\)

\(=\)\(42.\left(15+96\right)+42.\left(25+4\right)\)

\(=\)\(42.111+42.29\)

\(=\)\(42.140\)

\(=\)\(5880\)

ngu như con vịt

a) 15 . (27 + 18 + 6 ) + 15 . ( 23 +12 ) =  15. 51 + 15 . 35 = 765 + 525 = 1290

b) 14 . 35 . 5 + 10 . 25 . 7 + 20 . 70 = 2450 + 1750 + 1400 = 2452450

c) 53 . ( 51 + 4 ) + 53 . ( 49  + 96 ) + 53 = 53 . 55 + 53 . 145 + 53 = 2915 . 7685 = 22401775

d) 46 . ( 27 +75 ) +8 . ( 58 + 25 ) + 8 . ( 58 + 25 ) . 2 = 46 . 102 + 8 . 83 + 8 . 83 =  4692 + 664 + 664 = 6020