Х^2 + 3х - 18 = 0
D=b^2 -4ac = 3^2 - 4×1×(-18) = 9 + 72 = 81
х1 = -6; х2 = 3- корни уравнения
Ответ: х1 = -6; х2 = 3
32448:6=5408
Вот и всё ты просто
2cosx - 1 = 0 [0; 2pi]
2cosx = 1
cosx = 1/2
x = +- pi/3 + 2pik, k ∈ Z
1) k = -1
x1 = + pi/3 - 2pi = pi/3 - 6pi/3 = (pi-6pi)/3 = -5pi/3 ∉
x2 = - pi/3 - 2pi = - pi/3 - 6pi/3 = (-pi-6pi)/3 = -7pi/3 ∉
2) k = 0
x1 = +pi/3 ∈
x2 = - pi/3 ∉
3) k =1
x1 = +pi/3 + 2pi = pi/3 + 6pi/3 = (pi+6pi)/3 = 7pi/3 ∉
x2 = -pi/3 + 2pi = -pi/3 + 6pi/3 = (-pi+6pi)/3 = 5pi/3 ∈
4) k = 2
x1 = +pi/3 + 4pi = pi/3 + 12pi/3 = (pi+12pi)/3 = 13pi/3 ∉
x2 = -pi/3 + 4pi = -pi/3 + 12pi/3 = (-pi+12pi)/3 = 11pi/3 ∉
ОТВЕТ: pi/3; 5pi/3
15/49*14=15/(7*7) * (7*2)=(15*2)/7=30/7=4 2/7
11/36*27=11/(4*9) * (3*9)=(11*3)/4=33/4=8 1/4
18 * 13/48=(6*3) * 13/(6*8)=(3*13)/8=39/8=4 7/8
24 * 35/56=(8*3) * (7*5)/(8*7)=3*5=15
25 * 7/30=(5*5) * 7/(5*6)=(5*7)/6=35/6=5 5/6
32 * 11/48=(8*4) * 11/(8*6)=(4*11)/6=(2*11)/3=22/3=7 1/3
13/15 * 6=(13*2*3)/(3*5)=26/5=5 1/5
7/20 * 15=7/(4*5) * (5*3)=7*3/4=21/4=5 1/4
