1) = \(\frac{3}{5}\)

2) =\(\frac{6}{7}\)

3)\(\frac{9}{13}\)

4)\(\frac{4}{13}\)

Câu a) x là 3/8 nha.

Câu b) x là 1/3

Giải ra dùm vs 

viết p/s như nào vậy bạn

khó quá nhiw

a) 17 - 14( x + 1 ) = 13 - 4( x + 1 ) - 5( x - 3 )

<=> 17 - 14x - 14 = 13 - 4x - 4 - 5x + 15

<=> 17 - 14 - 13 + 4 - 15 = -4x - 5x + 14x 

<=> -21 = 5x

<=> x = -21/5

b) 7( 4x + 3 ) - 4( x - 1 ) = 15( x + 0, 75 ) + 7

<=> 28x + 21 - 4x + 4 = 15x + 45/4 + 7

<=> 28x - 4x - 15x = 45/4 + 7 - 21 - 4

<=> 9x = -27/4

<=> x = -3/4

c) 3x( x + 1 ) - 2x( x + 2 ) = x² - 1

<=> 3x² + 3x - 2x² - 4x = x² - 1

<=> 3x² + 3x - 2x² - 4x - x² = -1

<=> -x = -1

<=> x = 1 

a, \(17-14\left(x+1\right)=13-4\left(x+1\right)-5\left(x-3\right)\)

\(\Leftrightarrow17-14x-14=13-4x-4-5x+15\)

\(\Leftrightarrow3-14x=24-9x\Leftrightarrow3-14x-24+9x=0\)

\(\Leftrightarrow-21-5x=0\Leftrightarrow5x=-21\Leftrightarrow x=-\frac{21}{5}\)

b, \(7\left(4x+3\right)-4\left(x-1\right)=15\left(x+0,75\right)+7\)

\(\Leftrightarrow28x+21-4x+1=15x+\frac{45}{4}+7\)

\(\Leftrightarrow9x=-\frac{27}{4}\Leftrightarrow x=-\frac{3}{4}\)

c, \(3x\left(x+1\right)-2x\left(x+2\right)=x^2-1\)

\(\Leftrightarrow3x^2+3x-2x^2-4x=x^2-1\)

\(\Leftrightarrow x^2-x=x^2-1\Leftrightarrow x=1\)

bằng 6/7 nha bn

1)1/6 - - 5/6 = 1/6 + 5/6 = 1

2)6/13 - -14/39 = 6/13 + 14/39= 32/39

3)4/5 - 4/-18 = 4/5 + 4/18= 46/45

4)7/21 - 9/-36 = 7/21 + 9/36 = 7/12

5)-12/18 - -21/35  = -12/18 + 21/35 = -1/15

6)-3/21 - 6/42 = -2/7

7)-18/24 - 15/21 = -41/28

8)1/6 - 2/5 =-7/30

\(a,=\frac{7-1}{1.3.7}+\frac{9-3}{3.7.9}+\frac{13-7}{7.9.13}+\frac{15-9}{9.13.15}\)\(+\frac{19-13}{13.15.19}\)

\(=\frac{1}{1.3}-\frac{1}{3.7}+\frac{1}{3.7}-\frac{1}{7.9}+\frac{1}{7.9}-\frac{1}{9.13}+\frac{1}{9.13}-\frac{1}{13.15}+\frac{1}{13.15}-\frac{1}{15.19}\)

\(=\frac{1}{1.3}-\frac{1}{15.19}=\frac{95}{285}-\frac{1}{285}=\frac{94}{285}\)

\(b,=\frac{1}{6}.\left(\frac{6}{1.3.7}+\frac{6}{3.7.9}+\frac{6}{7.9.13}+\frac{6}{9.13.15}+\frac{6}{13.15.19}\right)\)

làm giống như trên

\(c,=\frac{1}{8}.\left(\frac{1}{1.2.3}+\frac{1}{2.3.4}+\frac{1}{3.4.5}+...+\frac{1}{48.49.50}\right)\)

\(=\frac{1}{16}.\left(\frac{2}{1.2.3}+\frac{2}{2.3.4}+\frac{2}{3.4.5}+...+\frac{2}{48.49.50}\right)\)

\(=\frac{1}{16}.\left(\frac{3-1}{1.2.3}+\frac{4-2}{2.3.4}+\frac{5-3}{3.4.5}+...+\frac{50-48}{48.49.50}\right)\)

\(=\frac{1}{16}.\left(\frac{1}{1.2}-\frac{1}{2.3}+\frac{1}{2.3}-\frac{1}{3.4}+\frac{1}{3.4}-\frac{1}{4.5}+...+\frac{1}{48.49}-\frac{1}{49.50}\right)\)

\(=\frac{1}{16}.\left(\frac{1}{2}-\frac{1}{2450}\right)=\frac{1}{16}.\left(\frac{1225}{2450}-\frac{1}{2450}\right)=\frac{153}{4900}\)

\(d,=\frac{5}{7}.\left(\frac{7}{1.5.8}+\frac{7}{5.8.12}+\frac{7}{8.12.15}+...+\frac{7}{33.36.40}\right)\)

\(=\frac{5}{7}.\left(\frac{8-1}{1.5.8}+\frac{12-5}{5.8.12}+\frac{15-8}{8.12.15}+...+\frac{40-33}{33.36.40}\right)\)

\(=\frac{5}{7}.\left(\frac{1}{1.5}-\frac{1}{5.8}+\frac{1}{5.8}-\frac{1}{8.12}+\frac{1}{8.12}-\frac{1}{12.15}+...+\frac{1}{33.36}-\frac{1}{36.40}\right)\)

\(=\frac{5}{7}.\left(\frac{1}{5}-\frac{1}{1440}\right)=\frac{5}{7}.\left(\frac{288}{1440}-\frac{1}{1440}\right)=\frac{41}{288}\)

P/S: . là nhân nha

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Cái này dễ thế mà ko bít lm

1/ 10(X-7)-8(X+5)=6(-5)+24
10x - 70 - 8x - 40 = -30 +24
2x - 110 = -6
2x = 104
x=52

2/ 8(X-|-7|)-6(X-2)=|-8|.6-50
8(x - 7) - 6(x-2) = 8.6 - 50
8x - 56 - 6x +12 =48 -50
2x - 44 = -2
2x = 42
x=21

3/ 2(4X-8)-7(3+X)=|-4|(3-2)
8x-16 - 21 - 7x = 4.1
x-37=4
x=41

4/ 12(X-4)=6(x-2)-16(X+3)=7|-4|
12x - 48 = 6x - 12 - 16x -48 =7.4
12x - 48 = 28
12x=76
x=19/3

5/ 4(X-5)-7(5-X)+10(5-X)=-3
4x - 20 -35 +7x + 50 -10x = -3
x - 5 = -3
x = -2
Chúc bạn học tốt!