1.
а = с * sinα,
a = 26 * sin 67°23' = 26 * 0,9231 = 24,
b = c * cosα,
b = 26 * 0,3846 = 10,
2.
c = b : sinβ,
c = 28 : 0,5282 = 53,
a = √(c² - b²),
a = √(53² - 28²) = √(2809 - 784) = √2025 = 45,
3.
b = √(c² - a²),
b = √(29² - 21²) = √(841 - 441) = √400 = 20,
4.
c = b : cosα,
c = 63 : 0,9689 = 65,
a = √(c² - b²),
a = √(65² - 63²) = √(4225 - 3969) = √256 = 16
<span>5*2=10 (км) - прошел пешеход за 2 часа</span>
А)125a³-8b³ = (5а)³ - (2b)³ = (5а-2b)((5а)²+5a·2b+(2b)²) =
= (5а-2b)(25а²+10ab+4b²)
<span>
б) a</span>³+27b³ = (а)³ + (3b)³ = (а+3b)(а²-a·3b+(3b)²) =
= (а+3b)(а²-3ab+9b²)
<span>
в) x</span>⁶-a⁶ = (x²)³ - (a²)³ = (x²-a²)((x²)²+x²·a²+(a²)²) =
= (x-a)(x+a)(x⁴+a²x²+a⁴)
<em>а) 9-3=6 стульев в одном ряду, 8*6=48 стульев в зале;</em>