a) 27 . 75 + 25 . 27 - 150 = 2025 + 675 - 150 = 2700 - 150 = 2550.

Lưu ý. Có thể dùng tính chất phân phối của phép nhân đối với phép cộng để nhẩm:

27 . 75 + 25 . 27 - 150 = 27 . (75 + 25) - 150 = 27 . 100 - 150 = 2700 - 150 = 2550.

b) 12 : {390 : [500 - (125 + 35 . 7)]} = 12 : {390 : [500 - (125 + 245)]}

= 12 : [390 : (500 - 370)] = 12 : (390 : 130) = 12 : 3 = 4.

a,27+75.25+27-150

= 27.(75+25)-150

=27.100-150

=2700-150

=2550

b,12:{390:[500-(125+35.7)]}

=12:{390:[500-(125+245)]}

=12:{390:[500-370]}

=12:{390:130}

=12:3

=4

Thank you very much

a, 25.(75 + 27 - 150 )

= 25 . (-48)

= - 1200

b, 12 : { 390 : [500 - 370 ]

= 12 : { 390 : 130 }

= 12 : 3

= 4

a) \(27.75+25.27-150\)

\(=27.\left(75+25\right)-150\)

\(=27.100-150\)

\(=2700-150\)

\(=2550\)

b) \(12:\left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)

\(=12:\left\{390:\left[500-370\right]\right\}\)

\(=12:\left\{390:130\right\}\)

\(=12:3\)

\(=4\)

các bạn ơi xin các bạn tội ngiệp cho tôi vài lik eSky Nguyễn

a).

= 27. (75+25)- 150

= 27. 100 -150

= 2700    - 150

= 2550

a, = 27 . ( 75 + 25 ) - 150 
    = 27 . 100 - 150
    = 2700 - 150
    = 2550
b, = 12 : { 390 : [ 500 - 370 ]
    = 12 : { 390 : 130 }
    = 12 : 3 
    = 4
 

a) 27.75+25.27-150=2025+675-150

                            =2700-150

                            =2550

b) 12:{390:[500-(125+35.7)]}=12:{390:[500-(125+245)]}

                                        =12:[390:(500-370)]

                                        =12:(390:130)

                                        =12:3

                                        =4

a) \(27\cdot75+25\cdot27-150\)

\(=27\cdot\left(75+25\right)-150\)

\(=27\cdot100-150\)

\(=2700-150\)

\(=2550\)

b) \(12:\left\{390:\left|500-\left(125+35\cdot7\right)\right|\right\}\)

\(=12:\left\{390:\left|500-\left(125+245\right)\right|\right\}\)

\(=12:\left\{390:\left|500-370\right|\right\}\)

\(=12:\left\{390:130\right\}\)

\(=12:3\)

\(=3\)

a) 27.(75+25)-150=27.100-150=2550

a)27.75+25.27-150

=27.(75+25)-150

=27.100-150

=2700-150

=2550

\(a,27.75+25.27-150\)

\(=27.\left(75+25\right)-150\)

\(=27.100-150\)

\(=2700-150\)

\(=2550\)

\(b,12:\left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)

\(=12:\left\{390:\left[500-\left(125+245\right)\right]\right\}\)

\(=12:\left[390:\left(500-370\right)\right]\)

\(=12:\left(390:130\right)\)

\(=12:3\)

\(=4\)

a: Ta có: \(\left(8\cdot5^7+5^6-5^5\right):5^5\)

\(=8\cdot5^2+5-1\)

\(=200+4=204\)

b: Ta có: \(\left(9^{30}-27^{19}\right):3^{57}+\left(125^9-25^{12}\right):5^{24}\)

\(=3^{60}:3^{57}-3^{57}:3^{57}+5^{27}:5^{24}-5^{24}:5^{24}\)

\(=27-1+125-1\)

=150

a. (8,5⁷ - 5⁵ + 5⁶) : 5⁵

= (8,5⁷ : 5⁵) - (5⁵ : 5⁵) + (5⁶ : 5⁵)

= 1,7² - 1 + 5

= 2,89 - 1 + 5

= 6,89

b. (9³⁰ - 27¹⁹) : 3⁵⁷ + (125⁹ - 25¹²) : 5²⁴

= (9³⁰ : 3⁵⁷) - (27¹⁹ : 3⁵⁷) + (125⁹ : 5²⁴) - (25¹² : 5²⁴)

= 3³ - 1 + 125 - 1

= 27 - 1 + 125 - 1

= 150

c. (10¹² + 5¹¹ . 2⁹ - 5¹³ - 2⁸) : 4 . 5⁵ . 10⁶

= (10¹² + 2,5 , 10¹⁰ - 5¹³ - 2⁸) : 1,25 . 10¹⁰

= (10¹² : 1,25 . 10¹⁰) + (2,5 . 10¹⁰ : 1,25 . 10¹⁰) - (5¹³ : 1,25 . 10¹⁰) - (2⁸ : 1,25 . 10¹⁰)

= 80 + 2 - \(\dfrac{25}{256}\) - \(\dfrac{1}{48828125}\)

= 81,90234373 \(\approx\) 82

a) 27.75+25.27-150

= 27.(75+25)-150

= 27.100-150

= 2550

b) 12:{390:[500-(125+75.7)]}

= 12:{390:(500-25.26)}

= 12:{390:[25.(20-26)]}

= 12:(390:(-150)]}

= 12 : \(\dfrac{-13}{5}\)

= \(\dfrac{-60}{13}\)

a)27.75+25.27-150=27.(75+25)-150=27.100-150=2700-150=26850

b)\(12:\left\{390:\left[500-\left(25.5+25.3.7\right)\right]\right\}\)

\(=12:\left\{390:\left[25.20-25.26\right]\right\}\)

\(=12:\left\{3.10.13:\left[-25.6\right]\right\}\)

\(=12:\left(\dfrac{-13}{5}\right)=-12.\dfrac{5}{13}=\dfrac{-60}{13}\)