1)12а-2(а^2+6a+9)=12a-2a^2+12a-18=-2a^2-18=<span>√-9
2)32a+2(a+8)=32a+2(a^2+16+64)=32a+2a^2+32a+128=2a^2+64a+128=a^2+32+64
3)x^2-8xy+16y^</span>2+10x^2+8xy=11X^2+16y^2= 16y^2=-55 Y=<span>√-55/16
4)8y^2-12xy-9x^2+12xy-4y^2=4y^2-9x^2=12-63=-51
5)6ab+3a^2-6ab+3b^2=6-9=-3
</span>
Log₈<span>(4-2x)≥2
</span>log₈(4-2x)≥log₈64
4-2x≥64
-2x≥64-4
-2x≥60
x≤-30
x∈(-oo;-30]
Cos(105)=(cos(60+45)=cos60cos45-sin45sin60=1/2*√2/2-√3/2*√2/2=√2(1-√3)/4
2)(-шексиз.,0]u[10,+шексиз.)
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