А) 4+3√-27=4+√9*(-27)=4+√-243
Б) 3√4+3√16=√36*√144=√5184=72
X + y = 12
x^2/y + y^2/x = 18
x^3 + y^3 = 18xy
(x+y)(x^2-xy+y^2) = 18xy
12(x^2-xy+y^2) = 18xy
2x^2 - 2xy + 2y^2 - 3xy = 0
x^2 - 5/2xy + y^2 = 0
x^2 - (2 + 1/2)xy + (2 * 1/2)y^2 = 0
(x - 2y)*(x - y/2) = 0
x + y = 12, x = 2y -> x = 8, y = 4
x + y = 12, y = 2x -> x = 4, y = 8
1)а) х^2+8х+16
б)а^2-4в+4в^2
В(3у+5)(3у-5)=9у^2-15у+15у-25=9у^2-25(формула разности квадратов )
2)с^2-в^2-5с^2+в^2=-4с^2
3)а)(4а-3)(4а+3)
Б)3х(х^2-25)=3х(х-5)(х+5)
В)2х(х+2у+у^2)
Дальше лень
9/7-3/27 2/19 31/30 <span>5/3 </span>
1) а1=1 a2=2 a3=5 a4=7
d=a2-a1 d=3-1=2
a10=a1+d9=1+9*2=19
sn=(a1+an)n\2 s
s12=(1+23)*2\2=24