648. Решите уравнение: a) 3(-2x+1)-2(x+18) = 7x-4(1-x); б) -4(5-2a)+3(a-4)=6(2-a)-5a; в) 3y(4y-1)-2y(6y-5) = 9y-8(3+y); г) 15x+6x(2-3x) = 9x(5-2x) - 36.

a) \(3(-2x+1)-2(x+18) = 7x-4(1-x)\) \(-6x + 3 - 2x - 36 = 7x - 4 + 4x\) \(-8x - 33 = 11x - 4\) \(-8x - 11x = -4 + 33\) \(-19x = 29\) \(x = -\frac{29}{19}\) Ответ: \(x = -\frac{29}{19}\) б) \(-4(5-2a)+3(a-4)=6(2-a)-5a\) \(-20 + 8a + 3a - 12 = 12 - 6a - 5a\) \(11a - 32 = 12 - 11a\) \(11a + 11a = 12 + 32\) \(22a = 44\) \(a = 2\) Ответ: \(a = 2\) в) \(3y(4y-1)-2y(6y-5) = 9y-8(3+y)\) \(12y^2 - 3y - 12y^2 + 10y = 9y - 24 - 8y\) \(7y = y - 24\) \(7y - y = -24\) \(6y = -24\) \(y = -4\) Ответ: \(y = -4\) г) \(15x + 6x(2 - 3x) = 9x(5 - 2x) - 36\) \(15x + 12x - 18x^2 = 45x - 18x^2 - 36\) \(27x - 18x^2 = 45x - 18x^2 - 36\) \(27x = 45x - 36\) \(27x - 45x = -36\) \(-18x = -36\) \(x = 2\) Ответ: \(x = 2\)