Z₁ + z₂ = 2 + 3i + 5 - 7i = (2 + 5) + i(3 - 7) = 7 - 4i
z₁ - z₂ = 2 + 3i - (5 - 7i) = 2 + 3i - 5 + 8i = (3 - 5) + i(3 + 8) = -2 + 11i
z₁/z₂ = (2 + 3i)/(5 - 7i) = (2 + 3i)(5 + 7i)/(5 - 7i)(5 + 7i) =
(10 + 14i + 15i + 21i²)/(25 - 7i²) = (10 - 21 + 29i)/(25 + 7) = -11/32 + 29i/32
z₁z₂ = (2 + 3i)(5 - 7i) = 10 - 14i + 15i - 21i² = 10 + i + 21 = 31 + i
|z₁| = √(2² + 3²) = √(4 + 9) = √13
|z₂| = √(5² + 7²) = √(25 + 49) = √74
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Корень (4-6х-х^2)= х+4 обе сторону возводим в квадрат то получиться
4-6х-х^2=(х+4)^2
4-6х-х^2=х^2+8х+16
4-6х-х^2-х^2-8х-16=0
-2х^2-14х-12=0
-2(х^2+7х+6)=0
х^2+7х+6=0
D=7^2-4×6=49-24=25
х1= -7+5/2=-2/2= -1
х2= -7-5/2= -12/2= -6
ответ: х1= -1, х2 = -6
2х+1)/2(2-х)=6
2х-3/6+6х-2х+1/2-х=6
2х-3/6+6х-2х+1/2-х-6=0
(2-х)*(2х-3)-(6+6х)*(2х+1)-6(6+6х)*(2-х)/(6+6х)*(2-х)
4х-6-2х²+3х-(12х+6+12х²+6х)+(-36-36х)*(2-х)/(6+6х)*(2-х)
4х-6-2х²+3х-(18х+6+12х²)-72+36х-72х+36х²/(6+6х)*(2-х)
4х-6-2х²+3х-18х+6+12х²-72+36х-72х+36х²/(6+6х)*(2-х)
-47х-84+22х²/(6+6х)*(2-х)=0
-47х-84+22х²=0
22х²-47х-84=0
Д=в²-4*а*с=-47²-4*22*(-84)=9601
х=47+√9601/44
х=47-√9601/44
Ответ х1=47-√9601/44 , х2=47+√9601/44