Question

[Bùi Quỳnh Anh]

Answer 1

[Nguyễn Lê Phước Thịnh]

a: 11+13+15+17+19

=(11+19)+(13+17)+15

=30+30+15

=75

b: \(122+2116+278+84\)

=(122+278)+(2116+84)

=400+2200

=2600

c: \(12\times125\times54\)

=1500x54

=81000

d: \(27\times36+27\times64=27\times\left(36+64\right)=27\times100=2700\)

e: \(25\text{x}37+25\text{x}63-150\)

=25x(37+63)-150

=25x100-150

=2500-150

=2350

f: \(425\text{x}74-27\text{x}425-1\)

=425x(74-27-1)

=425x46=19550

g: \(8\text{x}9\text{x}14+6\text{x}17\text{x}12+19\text{x}4\text{x}18\)

=14x72+17x72+19x72

=72x(14+17+19)

=50x72=3600

Answer 2

[Toru]

a) $11+13+15+17+19$

$=(11+19)+(13+17)+15$

$=30+30+15$

$=60+15=75$

b) $122+2116+278+84$

$=(122+278)+(2116+84)$

$=400+2200=2600$

c) $12\times125\times54$

$=3\times4\times125\times2\times27$

$=(4\times2)\times125\times(3\times27)$

$=8\times125\times81$

$=1000\times81=81000$

d) $27\times36+27\times64$

$=27\times(36+64)$

$=27\times100=2700$

e) $25\times37+25\times63-150$

$=25\times(37+63)-150$

$=25\times100-150$

$=2500-150=2350$

f) $425\times74-27\times425-425$

$=425\times(74-27-1)$

$=425\times(47-1)$

$=425\times46=19550$

g) $8\times9\times14+6\times17\times12+19\times4\times18$

$=(8\times9)\times14+(6\times12)\times17+(4\times18)\times19$

$=72\times14+72\times17+72\times19$

$=72\times(14+17+19)$

$=72\times(31+19)$

$=72\times50=3600$

$\mathtt{Toru}$