=2

=4

=6

=8

=10

Hôm sau mk k cho!!!

1+1=2

2+2=4

3+3=6

4+4=8

5+5=10

Kb nhé

2

4

6

8

10

tk mik nha

1 x 2 x 3 = 2x 3 + 1 = 7

2 x 3 x4 = 3 x 4 +2 = 14

3 x 4 x 5 = 4x 5 + 3 =23

4x5x6=5x6+4=34

k nha tớ k bn rồi

quy luật như sau :

1x2x3=2x3+1=7

2x3x4=3x4+2=14

3x4x5=4x5+3=23

4x5x6=5x6+4=34

1+2x3=7

2+3x4=14

3+4x5=23

=>4x5x6=34

a. 10 – 9 + 8 – 7 + 6 – 5 + 4 – 3 + 2 – 1

= (10 – 9) + (8 – 7) + (6 – 5) + (4 – 3) + (2 – 1)

= 1 + 1 + 1 + 1 + 1

= 5

b. 1 + 3 + 5 + 7 + 9 + 10 + 8 + 6 + 4 + 2 + 0

= (0 +10) +(1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) + 5

= 10 + 10 + 10 + 10 + 10 + 5

= 55

a) 10 - 9 + 8 - 7 + 6 - 5 + 4 - 3 + 2 - 1

= (10 - 9) + (8 - 7) + (6 - 5) + (4 - 3) + (2 - 1)

= 1 + 1 + 1 + 1 + 1

= 1 x 5

= 5

b) 1 + 3 + 5 + 7 + 9 + 10 + 8 + 6 + 4 + 2 + 0

= 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10

= (0 + 10) x 11 : 2

= 10 x 11 : 2

= 5 x 11

= 55

a)5

b)55

chúc bạn học tốt

S=(1-2)+(3-4)+(5-6)+...+(199-200)

S=(-1)+(-1)+...+(-1)

S=(-1).100=-100

S=1+(2-3)+(-4+5)+...+(98-99)+(-100+101)

S=1+(-1)+1+..+(-1)+1

S=1+25.(-1)+25.1

S=1+(-25)+25

S=1+0

=1

Nhanh nha mk cần gấp đó!

S= 1+(1-3)+3+(1-5)+5+(1-7)+........+199+(1-199)=200

\(\dfrac{1}{2}-\dfrac{2}{3}+\dfrac{3}{4}-\dfrac{4}{5}+\dfrac{5}{6}-\dfrac{6}{7}+\dfrac{7}{8}+\dfrac{6}{7}-\dfrac{5}{6}+\dfrac{4}{5}-\dfrac{3}{4}+\dfrac{2}{3}-\dfrac{1}{2}\)

\(=\left(\dfrac{1}{2}-\dfrac{1}{2}\right)+\left(-\dfrac{2}{3}+\dfrac{2}{3}\right)+....+\left(-\dfrac{6}{7}+\dfrac{6}{7}\right)+\dfrac{7}{8}\)

\(=\dfrac{7}{8}\)

Chúc bạn học tốt!!!

\(\dfrac{1}{2}-\dfrac{2}{3}+\dfrac{3}{4}-\dfrac{4}{5}+\dfrac{5}{6}-\dfrac{6}{7}+\dfrac{7}{8}+\dfrac{6}{7}-\dfrac{5}{6}+\dfrac{4}{5}-\dfrac{3}{4}+\dfrac{2}{3}-\dfrac{1}{2}\)

= \((\dfrac{1}{2}-\dfrac{1}{2})+(-\dfrac{2}{3}+\dfrac{2}{3})+...+(-\dfrac{6}{7}+\dfrac{6}{7})+\dfrac{7}{8}\)

=\(\dfrac{7}{8}\)

1/2-2/3+3/4-4/5+5/6-6/7+7/8+6/7-5/6+4/5-3/4+2/3-1/2

= \(\dfrac{7}{8}\)

= \(\frac{1}{2}\)- \(\frac{2}{3}\)+ (\(\frac{3}{4}\)- \(\frac{3}{4}\)) + ( -\(\frac{4}{5}\)+ \(\frac{4}{5}\)) + ( \(\frac{5}{6}-\frac{5}{6}\)) - \(\frac{6}{7}\)

= \(\frac{1}{2}-\frac{2}{3}-0-0-0-\frac{6}{7}\)

= \(\frac{1}{2}-\frac{2}{3}-\frac{6}{7}\)

=\(\frac{21}{42}-\frac{28}{42}-\frac{36}{42}\)

= \(\frac{-43}{42}\)

hjjjjhhbnjbbhhbbb

công chúa hoa anh đào nhắn linh tinh mình sẽ báo cáo

các bn lm đến đâu cx dc miễn là lm hộ mk cái ạ, ai đang lm vào nhắn tin vs mk để mk bít nha

a; \(-\dfrac{8}{3}+\dfrac{7}{5}-\dfrac{71}{15}< x< -\dfrac{13}{7}+\dfrac{19}{14}-\dfrac{7}{2}\)

              -\(\dfrac{19}{15}\) - \(\dfrac{71}{15}\) < \(x\) < -\(\dfrac{1}{2}\) - \(\dfrac{7}{2}\)

              -6 < \(x\) < -4

             vì \(x\) \(\in\) Z nên \(x\) = -5

- \(\dfrac{19}{6}+\dfrac{-15}{2}+\dfrac{11}{3}\) < \(x\) < - \(\dfrac{5}{4}\) + \(\dfrac{19}{12}\) - \(\dfrac{10}{3}\)

- \(\dfrac{32}{3}+\dfrac{11}{3}< x< \) \(\dfrac{1}{3}\) - \(\dfrac{10}{3}\)

-7 < \(x\) < - 3

Vì \(x\in\) Z nên \(x\in\) {-6;-5;-4}