2(5+2b)-4(4-2b)-12b=10+4b-16+8b-12b=-6+12b-12b=-6
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3(а-2) -(а+4) = 3а - 6 - а - 4 = 2а - 10
При а = -1,5 2а - 10 = 2*(-1,5) - 10 = -3 - 10 = -13
Ответ. -13
X²(-x²+3x+4)/(x²+x+2)>0
x²(x²-3x-4)/(x²+x+2)<0
x=0
x²-3x-4=0
x1+x2=3 U x1*x2=-4
x1=-1 U x2=4
x²+x+2=0
D=1-8=-7<0⇒при любом х выражение больше 0
+ _ _ +
-----------------(-1)--------(0)-------------(4)-------------
x∈(-1;0) U (0;4)
(6х-5ху)-(4х+ху) так? Если да, то вот:
6х-5ху-4х-ху=(6х-4х)+(-5ху-ху)= 2х-6ху.
M^2+2mn+n^2=(m+n)^2
m^2-n^2=(m-n)(m+n)
(m^2+2mn+n^2)/(m^2-n^2) :(m+n)=(m+n)^2/(m-n)(m+n)(m+n)=1/(m-n)