9!-8!-7!×8^2

=9!-8!-322560

=322560-322560

=0

\(9!-8!-7!.8^2\)

\(=8!.9-8!-7!.8.8\)

\(=8!\left(9-1\right)-8!.8\)

\(=8!-8!\)

\(=0\)

\(5\left[\left(85-35:7\right):2^3+3^2.10\right]-50\)

\(=5\left[\left(85-5\right):8+9.10\right]-50\)

\(=5\left[80:8+90\right]-50\)

\(=5\left[10+90\right]-50\)

\(=5.100-50\)

\(=500-50\)

\(=450\)

5.[ (85-35:7):2^3+3^2.10 ] - 50

=5.[(85-5):8+9.10  ]-50

=5.[80:8+9.10]-50

=5.[10+90]-50

=5.100-50

=5.2.50-50

=10.50-50.1

=50.(10-1)

=50.9

=450

đề có bị sai k bn?

6. [5x +35] = 360

5s+35=360:6

5x-35=60

5x=60+35

5x=95

x=95:5

x=19

2³–5³:5²+12.2²=8–5¹+12.4=8–5+48=3+48=51

\(2^3-5^3:5^2+12.2^2\)

\(=8-5+12.4\)

\(=8-5+48\)

\(=3+48\)

\(=51\)

_Chúc bạn học tốt_

Trả lời gấp cho mình với

i have a friend, her name is anh

I have a friend, she is Anh

1. 

a) (—7/3)³:(—7/3)²=(—7/3)^3–2=—7/3

b) (—4/9):(—4/9)³= (—4/9)^1–3=(—4/9)^—2=81/16

c) (1/5)¹⁰:(1/5)⁷=(1/5)^10–7=(1/5)³=1/125

2. 

a) —x/7 =1/—21

==> —x.(—21)=7.1

==> —x.(—21)=7

==> —x=7:(—21)

==> —x=—1/3

==> x=1/3

b) 4 2/5 . 0,5–1 3/7= 22/5 . 1/2 —10/7= 22.1/5.2–10/7=  11/5 —10/7= 77/35 — 50/35= 27/35

c) 3x²–2x=0

==> x³(3–2)=0

x³.1=0

x³=0:1

x³=0

==> x=0

c) 9x²–1=0

9x²=0+1

9x²=1

x²=1:9

x²=1/9

x²=1²/3² hoặc x²=(—1/3)²

Vậy x=1/3 hoặc x=—1/3

2-2+2-2=0

2-2+2:2=1

2:2+2:2=2

2+2-2:2=3

2+2-2+2=4

Cảm ơn bạn

có mình nè

mk có nè

\(2x+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+\frac{31}{30}+\frac{43}{42}+\frac{57}{56}+\frac{73}{72}+\frac{91}{90}=10\)
=> \(2x+\frac{6+1}{6}+\frac{12+1}{12}+....+\frac{90+1}{90}=10\)
=> \(2x+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}+10=10\)
=> \(2x+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}=0\)
=>\(2x+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{9.10}=0\)
=>\(2x+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{9}-\frac{1}{10}=0\)
=> \(2x-\frac{1}{10}=0\)
=>2x=\(\frac{1}{10}\)=> x=1/20
 

mình có bị nhầm chỗ dấu suy ra thứ 3. đáng lẽ ra biểu thức đó cộng 8 chứ k phải cộng 10 do mình sơ ý nên bạn hãy sủa lại chỗ ấy