(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27

= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)

= 145 × 100 – 143 × 100 + 47 × 1 – 47

= 100 × (145 – 143) + (47 – 47)

= 100 × 2 + 0

= 200

= 145 x (99+1) - 143 x ( 102-2) + 47 x ( 54 - 53) -20-27

= 145 x 100 - 143 x 100 + 47 x 1 -20-27

= 100 x ( 145 - 143 ) + 47 - 20 - 27

= 200 + 47 - 20 - 27

= 200

một tấm bìa hình thoi có tổng độ dài hai đường chéo bằng 126cm, biết độ dài đường chéo thứ nhất bằng 2/5 độ dài đường chéo thứ hai.Tính diện tích tấm bìa hình thoi đó.

(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27

= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)

= 145 × 100 – 143 × 100 + 47 × 1 – 47

= 100 × (145 – 143) + (47 – 47)

= 100 × 2 + 0

= 200

(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27

= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)

= 145 × 100 – 143 × 100 + 47 × 1 – 47

= 100 × (145 – 143) + (47 – 47)

= 100 × 2 + 0

= 200

a, 4 x 113 x 8 - 32 x 13

= (4 x 8) x 113 - 32 x 13

= 32 x 113 - 32 x 13

= 32 x (113 - 13)

= 32 x 100 = 3200

b , 54 x 227 + 45 x 227 + 227

= 227 x (54+45+1)

= 227 x 100

= 22 700

c, ( 145 x 99 + 145 ) - ( 143 x101 - 143 )

= 145 x (99+1) - 143 x (101 - 1)

= 145 x 100 - 143 x 100

= 100 x (145 - 143)

= 100 x 2

= 200

a) \(4\times113\times8-32\times13\)

\(=4\times8\times113-32\times13\)

\(=32\times113-32\times13\)

\(=32\times\left(113-13\right)\)

\(=32\times100\)

\(=3200\)

b) \(54\times227+45\times227+227\)

\(=227\times\left(54+45+1\right)\)

\(=227\times100\)

\(=22700\)

c) \(\left(145\times99+145\right)-\left(143\times101-143\right)\)

\(=145\times\left(99+1\right)-143\left(101-1\right)\)

\(=145\times100-143\times100\)

\(=14500-14300\)

\(=200\)

b: =47-47=0

a) – 3 < x < 2 => x ∈ {-2;-1;0;1}

b) − 4 21 < x 21 < 2 21 => x ∈ {-3;-2;-1;0;1}

c) 1 ≤  x ≤ 6 => x ∈ {-3;-2;-1;0;1}

d) -7 ≤  x ≤ -3 => x ∈ {-3;-2;-1;0;1}

A) 145 x (99 + 1) - 143 x (102 - 1)

= 145 x 100 - 143 x 101 = 145 x 100 - 143 x (100 + 1)

= 100 x (145 - 143)  - 143

= 200 - 143 = 57

B) 54 x 47 - 47 x 53 - 20 - 27

= 47 x (54 - 53) - (20 + 27)

= 47 x 1 - 47 = 0

= 200

co ai giải dõ ko ạ

\(=145\cdot100-143\cdot100+47\left(54-53-1\right)\)

\(=2\cdot100\)

=200

a) \(\left(145\times99+145\right)-\left(143\times102-143\right)\)

\(=\left[145\times\left(99+1\right)\right]-\left[143\times\left(102-1\right)\right]\)

\(=\left(145\times100\right)-\left(143\times101\right)\)

\(=14500-14443\)

\(=57\)

b) \(54\times47-47\times53-20-27\)

\(=47\times\left(54-53\right)-20-27\)

\(=47-20-27\)

\(=0\)

c) \(10000-47\times72-47\times28\)

\(=10000-47\times\left(72+28\right)\)

\(=10000-47\times100\)

\(=10000-4700\)

\(=5300\)

d) \(3457-27\times48-48\times73+6543\)

\(=\left(3457+6543\right)-48\times\left(27+73\right)\)

\(=10000-48\times100\)

\(=10000-4800\)

\(=5200\)