Объяснение:
1)(2a - 5b)·(... - ...) = 6a^3 - 15a^2*b - 14ab + ...;
6a^3 : 2a = 3a^2
14ab : 2a = 7b
(2a - 5b)(3a^2 - 7b) = 6a^3 - 15a^2*b - 14ab + 35b^2
2)(... - ...)·(6x^2 - 5y^2) = 12x^3 + 42x^2*y - ... - 35y^3;
12x^3 : 6x^2 = 2x
-35y^3 : (-5y^2) = 7y
(2x + 7y)(6x^2 - 5y^2) = 12x^3 + 42x^2*y - 10xy^2 - 35y^3
3)(3a + 4c)·(... + ...) = 20ac + 8bc + 6ab + ...;
20ac : 4c = 5a
6ab : 3a = 2b
(3a + 4c)(5a + 2b) = 20ac + 8bc + 6ab + 15a^2
4)(... + ...)·(2a + 5b) = ... + 5ab + 8ac + 20b
Здесь опечатка, в конце должно быть 20bc
5ab : 5b = a
8ac : 2a = 4c
(a + 4c)(2a + 5b) = 2a^2 + 5ab + 8ac + 20bc
Объяснение:
1)(2a - 5b)·(... - ...) = 6a^3 - 15a^2*b - 14ab + ...;
6a^3 : 2a = 3a^2
14ab : 2a = 7b
(2a - 5b)(3a^2 - 7b) = 6a^3 - 15a^2*b - 14ab + 35b^2
2)(... - ...)·(6x^2 - 5y^2) = 12x^3 + 42x^2*y - ... - 35y^3;
12x^3 : 6x^2 = 2x
-35y^3 : (-5y^2) = 7y
(2x + 7y)(6x^2 - 5y^2) = 12x^3 + 42x^2*y - 10xy^2 - 35y^3
3)(3a + 4c)·(... + ...) = 20ac + 8bc + 6ab + ...;
20ac : 4c = 5a
6ab : 3a = 2b
(3a + 4c)(5a + 2b) = 20ac + 8bc + 6ab + 15a^2
4)(... + ...)·(2a + 5b) = ... + 5ab + 8ac + 20b
Здесь опечатка, в конце должно быть 20bc
5ab : 5b = a
8ac : 2a = 4c
(a + 4c)(2a + 5b) = 2a^2 + 5ab + 8ac + 20bc
НОД(a,b) = 525/105 = 5,
a*b=525 = 3*175 = 3*5*5*7,
НОК =105 = 3*35 = 3*5*7,
НОД = 5.
a=3*5 = 15;
b = 5*7 = 35.
2) НОД = 7, a*b = 294=2*147 = 2*3*7*7,
НОК = 294/7 = 42 = 2*3*7.
a = 2*7 = 14
b = 3*7 = 21.
3) НОД = 5, a:b = 13:8 = 13/8 = 13*5/(8*5);
a = 13*5 = 65;
b = 8*5 = 40.
4) НОК = 224, a:b = 7:8,
224 = 2*2*56 = 2*2*7*8 = (2^5)*7,
a = 7*t; b=8*t,
b = (2^3)*t;
224 = 7*8*(2^2) = 7*8*4,
a = 7*4 = 28,
b = 8*4 = 32.
5) НОД = 3, НОК = 915 = 3*305 = 3*5*61,
a = 3*5 = 15,
b = 3*61 = 183.