29. ху=6
х=2
у=3
2×3=6
30. 2у+х=4
у=2; х=0
2×2+0=4
31. 10х-у=15
х=2; у=5
10×2-5=15
ИСПОЛЬЗУЕМ ФОРМУЛУ РАЗНОСТИ КВАДРАТОВ: ( Х-У)-(m+n)*(x-y)+(m+n).
AM=BM
OM расстояние ответ центра сфери.
до прямой AB;OM_|_AB
AB²=(7-1)²+(2-2)²+(5+3)²=36+64=100
AB=10
AM=10/2=5
∆OMA =>OM²=13²-5²=169-25=144
OM=12
X³(x - 2) + 2x²(x - 2) - 21x(x - 2) + 18(x - 2) = 0
(x - 2)*(x³ + 2x² - 21x + 18) = 0
(x - 2) *(x²(x - 1) + 3x(x - 1) - 18(x - 1)) = 0
(x - 2)*(x - 1)*(x² + 3x - 18) = 0
(x - 2)*(x - 1)*(x(x - 3) + 6(x - 3)) = 0
(x - 2)*(x - 1)*(x - 3)*(x + 6) = 0
x - 2 = 0
x = 2
x - 1 = 0
x = 1
x - 3 = 0
x = 3
<span>x + 6 = 0
x = - 6</span>
<span>log11(32)/log11(4) = <span>log11(2^5)/log11(2^2)=5<span>log11(2)/2log11(2)=5/2=2 1/2=2.5</span></span></span>