Вот, заняло минимум 30-40 секунд ..
(y-6)-(y-4)=3y
y-6-y+4-3y=0
-3y-2=0
-3y=2
y= - 2/3
Во всех выражениях формула - разность квадратов
a^2 - b^2 = (a + b)(a - b)
1. (<span>b + 3)(b - 3)= b^2 - 9;
</span><span>2. (2 - х)(2 + х) = 4 - x</span>^2;
3. <span>(k - y)(k + y) = </span>k^2 + y^2;
4. <span>(2c - 1)(2c + 1) = 4</span>c^2 - 1;
5. <span>(8х + 4a)(8х - 4a) = 64</span>х - 16а.
9x-4(x-7)≥-3
9x-4x+28≥-3
5x+28≥-3
5x≥-3-28
5x≥-31
x=-6 1/5 = -6,2
{-35+5x<0
{6-3x>-18
{x<7
{x<8
x∈(-∞; 7) => x<7
1) a³-2a²+a-2 = a(a²+1)-2(a²+1) = (a²+1)(a-2).
2) ab-ac-a²+bc = b(a+c)-a(c+a) = b(a+c)-a(a+c) = (a+c)(b-a).
3) x²-4x = x(x-4).
4) 3y³-6y⁶ = 3y³(1-2y³).
5) x⁴+x³ = x³(x+1).
6) 25x²-36y² = (5x-6y)(5x+6y).
7) 81a²-9b² = (<span>9a-3b)(9a+3b).</span>
8) 4x²-16y² = (2x-4y)(2x+4y).
9) x⁵-2x³ = x³(x²-2).
10) x⁴-2x² = x²(x²-2).
11) 64a-a³ = a(64-a²) = a(8-a)(8+a).
<span>12) x</span>⁵<span>+2x</span>⁴<span>-x-2 = x</span>⁴(x+2)-(x+2) = (x+2)(x⁴-1) = (x+2)(x²-1)(x²+1) =
(x+2)(x-1)(x+1)(x²+1).