Question

Đã trả lời bởi chuyên gia

Answer 1

$a) 8 \times 20 \times \frac{12}{24} \times 5 \times 10 = 8 \times 20 \times \frac{1}{2} \times 5 \times 10 = (8 \times 5) (20 \times 10) \times \frac{1}{2} = 40 \times 200 \times \frac{1}{2} = 4000 b) 21 \times 6 \times \frac{3}{18} \times 9 \times 7 = 21 \times 6 \times \frac{1}{6} \times 9 \times 7 = 21 \times 9 \times 7 = 1323 c) 22 / 5 \times 12 \times 5 / 22 = (\frac{22}{5} \times \frac{5}{22}) \times 12 = 12$

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Answer 2

$a) 8 \times 20 \times \frac{12}{24} \times 5 \times 10 = 8 \times 20 \times \frac{1}{2} \times 5 \times 10 = (8 \times 5) (20 \times 10) \times \frac{1}{2} = 40 \times 200 \times \frac{1}{2} = 4000 b) 21 \times 6 \times \frac{3}{18} \times 9 \times 7 = 21 \times 6 \times \frac{1}{6} \times 9 \times 7 = 21 \times 9 \times 7 = 1323 c) 22 / 5 \times 12 \times 5 / 22 = (\frac{22}{5} \times \frac{5}{22}) \times 12 = 12$

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Answer 3

a)8×20× $\frac{12}{24}$ ×5×10

=8×20× $\frac{1}{2}$ ×5×10

=8×(20×5)× $\frac{1}{2}$ ×10

=8×100× $\frac{1}{2}$ ×10

=800× $\frac{1}{2}$ ×10

=400×10

=4000

b)21×6× $\frac{3}{18}$ ×9×7

=21×6× $\frac{1}{6}$ ×9×7

=21×( $6 \times \frac{1}{6}$ )×9×7

=21×1×9×7

=21×9×7

=21×63

=1323

c) $\frac{22}{5}$ ×12× $\frac{5}{22}$

=( $\frac{1}{2}$ 0)×12

=1×12

=12