7*(1/7)в квадрате +62*1/7= <span>7/1*1/49 +62*1/7=1/7+62/7= 63/7= 9</span>
5^8 - 3^4 = (5^4 - 3^2)(5^4 + 3^2) = (5^2 - 3)(5^2 + 3^2)(5^4 + 3^2) = 22*(5^2 + 3^2)(5^4 + 3^2) = 11*2*(5^2 + 3^2)(5^4 + 3^2) => число 5^8-3^4 делится на 11.
-2sin(3x/2)sin(5x/2)=0
sin(3x/2)=0
3x/2=πk
x=2πk/3
0≤2πk/3≤4π
0≤2k≤12
0≤k≤6
k=0 x=0
k=1 x=2π/3
k=2 x=4π/3
k=3 x=2π
k=4 x=8π/3
k=5 x=10π/3
k=6 x=4π
sin(5x/2)=0
5x/2=πk
x=2πk/5
0≤2πk/5≤4π
0≤2k≤20
0≤k≤10
k=0 x=0
k=1 x=2π/5
k=2 x=4π/5
k=3 x=6π/5
k=4 x=8π/5
k=5 x=2π
k=6 x=12π/5
k=7 x=14π/5
k=8 x=16π/5
k=9 x=18π/5
x=10 x=4π
Решениеееееееееееееееееееееееееееееее