Розкрийте дужки і спростіть вираз 5)3/5(10а-5/9б)-4/7(2 5/8-а-21б

5)3/5(10а-5/9б)-4/7(2 5/8-а-21б

5 * (3/5) * (10a - (5/9)b) - 4/7 * (2 5/8 - a - 21b)

1. 5 * (3/5) = 3

2. (10a - (5/9)b) = 10a - (5/9)b

3. 2 5/8 = 21/8

4. -4/7 * (21/8 - a - 21b) = -12/7 + (4/7)a + (12/7)b

3 * (10a - (5/9)b) - (-12/7 + (4/7)a + (12/7)b)

30a - (15/9)b + (12/7 - (4/7)a - (12/7)b)

30a - (15/9)b - (12/7)b = 30a - (135/63)b - (108/63)b

30a - (15/9)b - (108/63)b = 30a - (5/3)b - (12/7)b

30a - (5/3)b - (12/7)b = 30a - ((5/3) + (12/7))b

30a - ((35/21) + (36/21))b

30a - (35/21 + 36/21)b = 30a - (71/21)b

30a - (71/21)b