Đặt tính rồi tính:

213 x 3= 639

208 x 4= 832

684 : 6= 114

630 : 9= 70

Đáp án:

B1

a) 17 b) 6 c) 112 d)9687

B2

100-x=33

x=100-33

x= 67

Ko bít

22222222222222222

a /   ( 85 x 99 + 85 ) - 50 x 101 - 58

    = ( 85 x 100 ) - 50 x 101 - 1

    = 8500 - 50 x 100

    8500 - 5000

     =  3500

b/ ( 207 + 162 - 108 ) : 9

    = 261 : 9

    = 29

tích mk nhé

a) (85 x 99 + 85) - 50 x 101 - 58

= (85 x 100) - 50 x 101 - 1

= 8500 - 50 x 100

= 8500 - 5000

= 3500

b) (207 + 162 - 108 ) : 9

= 261 : 9

= 29

\(\frac{2.4.6.8.10.12.14.16.18.20}{4.6.8.10.12.14.16.18.20.22}=\frac{2}{22}=\frac{1}{11}\)

vậy kết quả là \(\frac{1}{11}\)

\(\frac{2.4.6.8.10.12.14.16.18.20}{4.6.8.10.12.14.16.18.20.22}=\frac{2}{22}=\frac{1}{11}\)

C1: \(\left(\frac{3}{5}+\frac{4}{9}\right)\cdot\frac{3}{8}=\frac{47}{45}\cdot\frac{3}{8}=\frac{141}{360}=\frac{47}{120}\)

C2: \(\left(\frac{3}{5}+\frac{4}{9}\right)\cdot\frac{3}{8}=\frac{3}{5}\cdot\frac{3}{8}+\frac{4}{9}\cdot\frac{3}{8}=\frac{9}{40}+\frac{12}{72}=\frac{47}{120}\)

C1: ( \(\frac{3}{5}+\frac{4}{9}\) ) * \(\frac{3}{8}\) 

= \(\frac{47}{45}\) * \(\frac{3}{8}\) = \(\frac{47}{120}\) 

C2: Đề

= 3/5 * 3/8 + 4/9 * 3/8

= 9/40 + 1/6

= 47/120