(x - 6)(4x - 6) = 0
4x² - 6x - 24x + 36 = 0
4x² - 30x + 36 = 0
2x² - 15x + 18 = 0
D = b² - 4ac = 225 - 4 × 2 × 18 = 225 - 144 = 81 = 9²
x1 = ( 15 + 9) / 4 = 6
x2 = ( 15 - 9) / 4 = 1,5
Ответ: x1 = 6, x2 = 1,5.
-8x+2y=5||*(-4)
x+5y=-2||*2
-3x+y=9||*(-2)
28x=-2
(5√2-√6)(5√2+√6)=(5√2)²-(√6)²=25*2-6=44