5x-y=4
-2x+y=5
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3x=9
x=3
1) 6cd.2ac=6.2.a.d.c.c=12ac²d
2)4m.(-5n).(-8k)=4.(-5).(-8).m.n.k=160mnk
3√2*√50=3√2√(25*2)=3*5√2√2=3*5*2=30
<span>lg^2x-5lg+2=0
ОДЗ: x > 0
D = 25 - 4*1*2 = 16
1) lgx = (5 - 4)/2
lgx = 1/2
x1 = 10^(1/2)
x = </span>√(10)
2) lgx = (5 + 4)/2
lgx = 4,5
x2 = 10^(4,5)
1) x^2-2x-4x+8-(x^2-3x-x+3)=x^2-6x+8-(x^2-4x+3)=x^2-6x+8-x^2+4x-3=-2x-3
x=1(3/4)
-2*7/4-3=-14/4-3=-(14+12)/4=-26/4=-6(2/4)=-6,5
2)a^2-a-5a+5-(a^2-3a+2a-6)=a^2-6a+5-a^2+a+6=-5a+11=11-5a
a=-2(3/5)=-2,6
11-5*(-2,6)=11+13=24
3)x^2-3x-2x+6+x^2-5x+6x-30-2x^2+14x-26=2x^2-4x-24-2x^2+14x-26=10x-50
x=5,6
10x-50=10*5,6-50=56-50=6