√4*√7- 2√2a 2√7-2√2a 2(√7-√2a) =____________=_______________= __________________=
5((√2a)²-(√7)²) 5(√2a-√7)(√2a+√7) <span> 5(√2a+√7) ( √2a-√7)</span>
<span> 2</span>
<span>=_________</span>
<span>-5(√2a+√7
</span>
Sin²4x - 3sin4x + 2 = 0
a = sin4x, -1 ⩽ a ⩽ 1
a² - 3a + 2 = 0
a² - 2a - a + 2 = 0
(a - 2)(a - 1) = 1
a₁ = 1, [a₂ = 2]!
sin4x = 1
4x = π/2 + 2πn, n ∈ ℤ
x = π/8 + πn/4, n ∈ ℤ
Х-y=5
x²-y²=185
x=5+y
(5+y)²-y²=185
y=16
x=5+16=21