5x^2+20x=0
x(5x+20)=0
x= 0 или 5х+20 = 0;
x=-20/5=-4
Ответ: x= 0, x=-4.
(3x - 5)² - (x + 3)² = (3x - 5 - x - 3)(3x - 5 + x + 3) = (2x - 8)(4x - 2)
a^6 - (a + 4)² = (a³ - a - 4)(a³ + a + 4)
(a + b - c)² - (a - b + c)² = (a + b - c - a + b - c)(a + b - c + a - b + c) = 2a(2b - 2c) = 4a(b - c)
<span> (a-2)</span>³ = a³-6a²+12a-8.<span>
(3a+b)</span>³ = 27a³+27a²b+9ab²+b³.<span>
(c-4d)</span>³ = c³-12c²d+48cd²-64d³.<span>
(a+0,3bc)</span>³ = a³+0,9a²bc+0,27ab²c²+0,27b³c³.