a) \(26+150+74=\left(26+74\right)+150=100+150=250\).

b) \(35.46+54.35=35.\left(46+54\right)=35.100=3500\).

c) \(\left(-31\right)+\left[20-\left(7-4\right)^2\right]=\left(-31\right)+20-3^2=\left[\left(-31\right)-9\right]+20=-40+20=-20\)

a , ( 456 . 11 - 912 ) . 37 : 13 : 74

= ( 5016 - 912 ) . 37 : 13 : 74

= 4014 . 37 : 13 : 74

= \(\frac{2025}{13}\)

b , [ ( 315 + 372 ) . 3 + ( 372 + 315 ) .7 ] : ( 26 . 13 + 74 . 14 )

= [ 687 . 3 + 687 . 7 ] : ( 338 + 1036 )

= [ 687 . ( 3 + 7 ) ] : 1374

= 6870 : 1374

= 5

a) \(35.26+35.74\)

\(=35\left(26+74\right)\)

\(=35.100\)

\(=3500\)

b) \(6^7:6^5+3.3^2\)

\(=6^2+3^3\)

\(=36+27\)

\(=63\)

d) Ta có: \(-8+\left(-14\right)+34+\left(-12\right)\)

\(=-8-14+34-12\)

\(=-20+20\)

\(=-0\)

e) Ta có: \(\left(-7\right)+\left(-20\right)+57+\left(-30\right)\)

\(=\left(-7+57\right)+\left(-20-30\right)\)

\(=50-50=0\)

f) Ta có: \(300-\left(-180\right)-120-42\)

\(=300+180-120-42\)

\(=258+60=318\)

d, Ta có : \(\left(-8\right)+\left(-14\right)+34+\left(-12\right)\)

\(=-\left(8+12\right)+34-14=-20+20=0\)

e, Ta có : \(\left(-7\right)+\left(-20\right)+57+\left(-30\right)\)

\(=-\left(30+20\right)+57-7=-50+50=0\)

f, Ta có : \(300-\left(-180\right)-120-42=318\)

d,=-8-14+34-12=(-8+34)-(14+12)

=26-26=0

e,=-7-20+57-30=(-7+57)-(20+30)

=50-50=0

f,=300+180-120-42=300+40-42=298

thực hiện phép tính bằng cách hợp lí (nếu có thể)

a,136:{[(468+332):160-5]+68}+2014

= 136 : { [ ( 468 + 332 ) : 160 - 5 ] + 68 } + 2014

= 136 : { [ 800 : 160 - 5 ] + 68 } + 2014

= 136 : { [ 5 - 5 ] + 68 } + 2014

= 136 : { 0 + 68 } + 2014

= 136 : 68 + 2014

= 2 + 2014

= 2016 

\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)

\(=136:\left[\left(800:160-5\right)+68\right]+2014\)

\(=136:\left[\left(5-5\right)+68\right]+2014\)

\(=136:\left(0+68\right)+2014\)

\(=136:68+2014=2+2014\)

\(=2016\)

\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)

\(=136:\left\{\left[800:160-5\right]+68\right\}+2014\)

\(=136:\left\{\left[5-5\right]+68\right\}+2014\)

\(=136:\left\{0+68\right\}+2014\)

\(=136:68+2014\)

\(=2+2014\)

\(=2016\)

a) \(26+173+74+27\)

\(=\left(26+74\right)+\left(173+27\right)\)

\(=100+200\)

\(=300\)

b) \(75\cdot37+89\cdot46+75\cdot52-89\cdot21\)

\(=75\cdot\left(37+52\right)+89\cdot\left(46-21\right)\)

\(=75\cdot89+89\cdot25\)

\(=89\cdot\left(75+25\right)\)

\(=89\cdot100\)

\(=8900\)

c) \(2^7:2^2+5^4:5^3\cdot2^4-3\cdot2^5\)

\(=2^{7-2}+5^{4-3}\cdot2^4-3\cdot2^5\)

\(=2^5+5\cdot2^4-3\cdot2^5\)

\(=2^4\cdot\left(2+5-3\cdot2\right)\)

\(=2^4\cdot\left(7-6\right)\)

\(=2^4\)

\(=16\)

d) \(100:\left\{250:\left[450-\left(4\cdot5^3-2^2\cdot25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(4\cdot5^3-4\cdot5^2\right)\right]\right\}\)

\(=100:\left[250:\left(450-4\cdot5^2\cdot4\right)\right]\)

\(=100:\left[250:\left(450-400\right)\right]\)

\(=100:\left(250:50\right)\)

\(=100:5\)

\(=20\)