Question

Помогите пожалуйста Тема: "Сложение и вычитание дробей с разными знаменателями".Представьте в виде дроби:1)5/x + 6/y=2)9/x - 5/xy=3)4/12ab - 11/18ab=4)5m/3ab - 7n/5a²b=5)3x-1/x² + x-9/3x=6)1/2ab² - 1/6a²=7)3b+7/3b - b²-5/b²=8)y/4+y - 2/5=9)c+3/c² - 1/c=10)x-y/x² - y-x/xy=11)3x+2/5x - 5x+3y/10xy - y-1/2y=12)(a-b)²/18b - (a-b)²/12b=13)6y + 1/y=

Answer 1

Ответ:

Объяснение:

1) 5/x + 6/y= (5y + 6x)/(xy)

2) 9/x - 5/xy= (9y - 5)/(xy)

3) 4/12ab - 11/18ab= (4*3 - 11*2)/(36ab) = -10/(36ab) = -5/(18ab)

4) 5m/3ab - 7n/5a²b= (5m*5a - 7n*3)/(15a^2*b) = (25am - 21n)/(15a^2*b)

5) (3x-1)/x² + (x-9)/3x= (3(3x-1) + x(x-9))/(3x^2) =

= (9x - 3 + x^2 - 9x)/(3x^2) = (x^2 - 3)/(3x^2)

6) 1/2ab² - 1/6a²= (3a - b^2)/(6a^2*b^2)

7) (3b+7)/3b - (b²-5)/b²= (b(3b+7) - 3(b^2 - 5))/(3b^2) =

= (3b^2 + 7b - 3b^2 + 15)/(3b^2) = (7b + 15)/(3b^2)

8) y/4+y - 2/5= (5y - 2(4+y))/(5(4+y)) = (5y-8-2y)/(20+5y) = (3y-8)/(5y+20)

9) c+3/c² - 1/c= (c+3 - c)/c^2 = 3/c^2

10) (x-y)/x² - (y-x)/xy= (y(x-y) - x(y-x))/(x^2*y) =

= (xy - y^2 - xy + x^2)/(x^2*y) = (x^2 - y^2)/(x^2*y)

11) (3x+2)/5x - (5x+3y)/10xy - (y-1)/2y= (2y(3x+2) - (5x+3y) - 5x(y-1))/(10xy) =

= (6xy+4y-5x-3y-5xy+5x)/(10xy) = (xy+y)/(10xy) = y(x+1)/(10xy) = (x+1)/(10x)

12) (a-b)²/18b - (a-b)²/12b= (2(a-b)^2 - 3(a-b)^2)/(36b) = -(a-b)^2/(36b)

13) 6y + 1/y= (6y^2 + 1)/y

Answer 2

1) 5/x + 6/y = (5y + 6x)/(xy) 2) 9/x - 5/xy = (9y - 5x)/(xy) 3) 4/12ab - 11/18ab = (2/6ab) - (11/18ab) = (3/18ab) - (11/18ab) = (-8/18ab) = -4/9ab 4) 5m/3ab + 7n/5a²b = (25m/15a²b) + (21n/15a²b) = (25m + 21n)/15a²b 5) (3x-1)/x² + (x-9)/3x = (3x^2 - x - x^3 + 9x^2)/(3x^3) = (12x^2 - x - x^3)/(3x^3) 6) 1/2ab² + 1/6a² = (3a² + ab²)/(6a²b²) 7) 3b+7/3b - b²-5/b² = (3b^2 + 7 - 3b^3 - 15)/(3b^3) = (-3b^3 + 3b^2 - 8)/(3b^3) 8) y/4 + y/5 = (5y + 4y)/20 = 9y/20 9) c+3/c² - 1/c = (c^2 + 3c - 1)/(c²) 10) x-y/x² - y-x/xy = (xy - y² - x² + xy)/(x²xy) = (2xy - x² - y²)/(x²xy) 11) 3x+2/5x + 5x+3y/10xy - y-1/2y = (6x^2y + 4xy + 25x^2 + 15xy - 10x - 5y^2 - 2y)/(10xy^2) 12) (a-b)²/18b - (a-b)²/12b = (3(a-b)² - 2(a-b)²)/(36b) = (a-b)²/36b 13) 6y + 1/y = (6y² + 1)/(y)