45 x ( 55 + 117 ) + 55 x ( 117 - 45 )

= (45 x 55 - 45 x 55) + (45 + 55) x 117

= 0  + 100 x 117 = 11700

\(45\times\left(55+117\right)+55\times\left(117-45\right)\)

\(=45\times55+45\times117+55\times117-55\times45\)

\(=\left(45\times55-45\times55\right)+45\times117+55\times117\)

\(=45\times117+55\times117\)

\(=117\times\left(45+55\right)\)

\(=117\times100\)

\(=11700\)

3025

4875

625

1225

55 x 55 =3025

75 x 65 =4875

25 x 25 =625

35 x 35 =1225

55 x 55 =3025

75 x 65 = 4875

25 x 25 =625

35 x 35 = 1225

đề thiếu                                  

b) 35 x 24 + 35 x 76 +55 x 19 +55 x 91

= 35 x ( 24 + 76 ) + 55 x ( 19 + 91 )

= 35 x100 +55 x 100

= 100 x ( 55 + 35 )

= 90 x 100 =9 000

c) \(6\cdot25\cdot4+4\cdot19\cdot6-2\cdot14\cdot12\)

\(=24\cdot25+24\cdot19-24\cdot14\)

\(=24\left(25+19-14\right)\)

\(=24\cdot30=720\)

d) \(19\cdot64+76\cdot34\)

\(=76\cdot19+76\cdot34\)

\(=76\left(19+34\right)=76\cdot53=4028\)

a) 2 x 16 x 50 x 25

= ( 2 x 50 ) x ( 16 x 25 )

= 100 x 400 

= 40 000

a: \(542\cdot7+542\cdot2+542\)

\(=542\left(7+2+1\right)\)

\(=542\cdot10=5420\)

b: \(\left(126\cdot35+157\cdot55\right)\cdot\left(132-6\cdot22\right)\)

\(=\left(126\cdot35+157\cdot55\right)\left(132-132\right)\)

\(=0\cdot\left(126\cdot35+157\cdot55\right)\)

=0

c: \(897\cdot99+897\)

\(=897\left(99+1\right)\)

\(=897\cdot100=89700\)

a) 542 x 7 + 542 x 2 + 542

= 542 x 7 + 542 x 2 + 542 x 1

= 542 x (7 + 2 + 1)

= 542 x 10

= 5420

b) (126 x 35 + 157 x 55) x (132 - 6 x 22)

= (126 x 35 + 157 x 55) x (132 - 132)

= (126 x 35 + 157 x 55) x 0 (Số bất kỳ nào nhân với 0 vẫn = 0)

= 0

c) 897 x 99 + 897

= 897 x 99 + 897 x 1

= 897 x (99 + 1)

= 897 x 100

= 89700

a) \(542.7+542.2+542\)

\(=542.\left(2+7+1\right)\)

\(=542.10=5420\)

b) \(\left(126.35+157.55\right).\left(132-6.22\right)\)

\(=13045.0=0\)

c) \(897.99+897\)

\(=897.\left(99+1\right)\)

\(=897.100=89700\)

25 + 25 x 3

= 25 x ( 1 + 3 )

= 25 x 4

= 100

35 + 45 + 55 + 65

= ( 35 + 65 ) + ( 45 + 55 )

= 100 + 100

= 200

25 + 25 x 3

= 25 x 75

= 100

35 + 45 + 55 + 65

= ( 35 + 65 ) + ( 55 + 45 )

= 100 + 100

= 200

25 + 25 x 3

= 25 x ( 3 + 1 )

= 25 x 4

= 100

35 + 45 + 55 + 65

= ( 35 + 65 ) + ( 45 + 55 )

= 100 + 100

= 200

\(x\times95-x\times35-x\times55=225\\ x\times\left(95-35-55\right)=225\\ x\times5=225\\ x=225:5\\ x=45\)

[ { 4 x X + 28 } x 3 + 55 ] : 5 = 35

[ { 4 x X + 28 } x 3 + 55 ] = 35 x 5

[ { 4 x X + 28 } x 3 + 55 ] = 175

{ 4 x X + 28 } x 3 = 175 - 55

{ 4 x X + 28 } x 3 = 120

4 x X + 28 = 120 : 3

4 x X + 28 = 40

4 x X = 40 - 28

4 x X = 12

X = 12 : 4

X = 3

(4*X+28)*3+55=35*5

=>(4*X+28)*3+55=175

=>(4*X+28)*3=120

=>4*X+28=40

=>4*X=12

=>X=3