2) [m]\frac{(4 \cdot 5)^7}{4^5 \cdot 5^7} = \frac{4^7 \cdot 5^7}{4^5 \cdot 5^7} = \frac{4^7}{4^5} = 4^2 = 16[/m]
3) 1 - 10x = 5x + 10
1 - 10 = 5x + 10x
15x = -9
x = -9/15 = -3/5 = -0,6
4) а) 3x - 2(x - 5) ≤ -6
3x - 2x + 10 ≤ -6
x ≤ -16
x ∈ (-∞; -16]
б) x^2 ≤ 9
x^2 - 9 ≤ 0
(x + 3)(x - 3) ≤ 0
x ∈ [-3; 3]