ответ: 1 ) x = 2 ; 2 ) х = 4 .
Пошаговое объяснение:
1 . ( x - 4 )/( x - 3 ) + 6/( x² - 9 ) - 0,8 = 0 ; │ X ( x² - 9 ) ≠ 0
( x - 4 )(x + 3 ) + 6 - 0,8( x² - 9 ) = 0 ;
x² - x - 12 + 6 - 0,8x²+ 7,2 = 0 ;
0,2x² - x + 1,2 = 0 ; │ X 5
x² - 5x + 6 = 0 ; D = 25 - 24 = 1 > 0 ; x₁ = 2 ; x₂ = 3 - не підходить
2 . ( x - 7 )/( x - 5 ) - 7/ (x + 5 ) + 20/( x² - 25 ) = 0; X ( x² - 25 ) ≠ 0
( x - 7 )( x +5 ) - 7( x - 5 ) + 20 = 0 ;
x² - 2x - 35 - 7x + 35 + 20 = 0;
x² - 9x + 20 = 0 ; D = 81 - 80 = 1 > 0 ; x ₁ = 4 ; x₂= 5 - не підходить
(1 3/25 - 4/25) : (1 - 2/5) * (10 - 9 1/16) = 1 1/2
1) 1 3/25 - 4/25 = 24/25
2) 1 - 2/5 = 3/5
3) 10 - 9 1/16 = 15/16
4) 24/25 : 3/5 = 24/25 * 5/3 = 8/5
5) 8/5 * 15/16 = 3/2 = 1 1/2
ответ: 1 1/2
(1 + 7/23) * (2 - 4/25) : ( 99 - 98 1/5) = 3
1) 1 + 7/23 = 1 7/23
2) 2 - 4/25 = 1 21/25
3) 99 - 98 1/5 = 4/5
4) 1 7/23 * 1 21/25 = 30/23 * 46/25 = 12/5
5) 12/5 : 4/5 = 12/5 * 5/4 = 3
ответ: 3
(7/15 + 23/45) * (1 4/11 + 5/22) : (11 5/18 - 7 1/9) = 28/75
1) 7/15 + 23/45 = 21/45 + 23/45 = 44/45
2) 1 4/11 + 5/22 = 1 8/22 + 5/22 = 1 13/22
3) 11 5/18 - 7 1/9 = 11 5/18 - 7 2/18 = 4 3/18 = 4 1/6
4) 44/45 * 1 13/22 = 44/45 * 35/22 = 14/9
5) 14/9 : 4 1/6 = 14/9 : 25/6 = 14/9 * 6/25 = 28/75
ответ: 28/75
(15 - 13 4/97) * ( 1 4/5 + 7/50) : (12 7/10 - 7) = 2/3
1) 15 - 13 4/97 = 1 93/97
2) 1 4/5 + 7/50 = 1 40/50 + 7/50 = 1 47/50
3) 12 7/10 - 7 = 5 7/10
4) 1 93/97 * 1 47/50 = 190/97 * 97/50 = 19/5
5) 19/5 : 5 7/10 = 19/5 : 57/10 = 19/5 * 10/57 = 2/3
ответ: 2/3
(1 3/13 + 14/65) : ( 21 - 18 6/13) : (5 10/11 - 5 3/55) = 2/3
1) 1 3/13 + 14/65 = 1 15/65 + 14/65 = 1 29/65
2) 21 - 18 6/13 = 2 7/13
3) 5 10/11 - 5 3/55 = 5 50/55 - 5 3/55 = 47/55
4) 1 29/65 : 2 7/13 = 94/65 : 33/13 = 94/65 * 13/33 = 94/165
5) 94/165 : 47/55 = 94/165 * 55/47 =2/3
ответ: 2/3
(6 2/11 - 5 1/77) * (17/35 + 1 2/5) *(8 1/9 - 5 7/18) = 6
1) 6 2/11 - 5 1/77 = 6 14/77 - 5 1/77 = 1 13/77
2) 17/35 + 1 2/5 = 17/35 + 1 14/35 = 1 31/35
3) 8 1/9 - 5 7/18 = 8 2/18 - 5 7/18 = 2 13/18
4) 1 13/77 * 1 31/35 = 90/77 * 66/35 = 108/49
5) 108/49 * 2 13/18 = 108/49 * 49/18 = 6
ответ: 6
Пошаговое объяснение: