B1

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

B2

100-x=33

x=100-33

x= 67

Ko bít

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Cgcr

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

4+8+7+9+5+2+1+3*0=36

4 + 8+7+9+5+2 +1 +0

\(a,2\times3=6\)

\(6\times2=12\)

\(10\times2=20\)

\(1\times2=2\)

\(b,5\times7=35\)

\(9\times5=45\)

\(5\times8=40\)

\(1\times5=5\)

[(1+9)+(2+8)+(3+7)+(4+6)+5]x2

=(10+10+10+10+5)x2

=45x2

=90

50x2+2x10

=2x(50+10)

=2x60

=120

\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)

1+2+3+4+5+6+7+8+9

=(1+9)+(2+8)+(3+7)+(4+6)+5

=10+10+10+10+5

=45

123+546+789=1458

Chúc bạn học giỏi!!!

Nhớ k nha vì mik làm xong đầu đó

máy tính đâu

9 x 5 = 45

9 x 6 = 54

9 x 7 = 63

9 x 8 = 72

9 x 9 = 81

45

54

63

91

\(4\Omega6=4+5+6+7+8+9=39\)

khờ thế !

64 x 4 + 18 x 4+ 9 x 8

= 64 x4 + 18 x4 + 9 x 2 x 4

= 64 x 4+ 18 x 4+ 18 x 4

= 4x(64+18+18)

= 4 x 100

= 400

64 x 4 + 18 x 4 + 9 x 8

= 64 x 4 + 18 x 4 + 9 x 2 x 4

= 64 x 4 + 18 x 4 + 18 x 4

= ( 64 + 18 + 18 ) x 4

= 100 x 4

= 400