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)\(27.75+25.27-150=27\left(75+25\right)-150\)
\(=27.100-150\)
\(=2700-150\)
\(=2550\)
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) 27 . 75 + 25 . 27 - 150 b) 12 : { 390 : [ 500 - ( 125 + 35 . 7 ) ] }
= 27 . ( 75 + 25 ) - 150 = 12 : { 390 : [ 500 - ( 125 + 245 ) ] }
= 27 . 100 - 150 = 12 : { 390 : [ 500 - 370 ] }
= 2700 - 150 = 12 : { 390 : 130 }
= 2550 = 12 : 3
= 4
Ta có:
\(a)27.75+25.27-150\)
\(=27.\left(75+25\right)-150\)
\(=27.100-150\)
\(=2700-150\)
\(=2550\)
Vậy ...
\(b)12\div\left\{390\div\left[500-\left(125+35.7\right)\right]\right\}\)
\(=12\div\left\{390\div\left[500-125+245\right]\right\}\)
\(=12\div\left[390\div\left(500-370\right)\right]\)
\(=12\div\left(390\div130\right)\)
\(=12\div3\)
\(=4\)
Vậy ...
a) 27 x 75 + 25 x 27 - 150
= 27 x (75 + 25) - 150
= 27 x 100 - 150
= 2700 - 150
= 2550
b) 12 : {390 : [500 - (125 + 35 x 7)]}
= 12 : {390 : [500 - (125 + 245)]}
= 12 : [390 : (500 - 370)]
= 12 : (390 : 130)
= 12 : 3
= 4
Học tốt!!!
