X³(x - 2) + 2x²(x - 2) - 21x(x - 2) + 18(x - 2) = 0
(x - 2)*(x³ + 2x² - 21x + 18) = 0
(x - 2) *(x²(x - 1) + 3x(x - 1) - 18(x - 1)) = 0
(x - 2)*(x - 1)*(x² + 3x - 18) = 0
(x - 2)*(x - 1)*(x(x - 3) + 6(x - 3)) = 0
(x - 2)*(x - 1)*(x - 3)*(x + 6) = 0
x - 2 = 0
x = 2
x - 1 = 0
x = 1
x - 3 = 0
x = 3
<span>x + 6 = 0
x = - 6</span>
<span>2a+3b=0.6(5a+3b)
3b-1,8b=3a-2a
a=1,2b
(a²+3ab)/b²=(1,44b²+3,6b²)/b²=5,04b²/b²=5,04</span>
3x-15-2x-8= -5x+1; 3x-2x+5x=1+8+15; 6x=24; x=24:6; x=4. Ответ: x=4.