4. Решить уравнение: 1) 80х- х²=0 2) 6x²-24=0 3) 12-4(x+2)=-6x-3

1) 80x - x² = 0 => x(80 - x) = 0 => x₁ = 0, x₂ = 80.

2) 6x² - 24 = 0 => 6x² = 24 => x² = 4 => x₁ = 2, x₂ = -2.

3) 12 - 4(x + 2) = -6x - 3 => 12 - 4x - 8 = -6x - 3 => 4 - 4x = -6x - 3 => 2x = -7 => x = -3.5.