Ответ & & & & & & & & & & & & & & &
[(7,8²-7,8×17):(12×17)]×[(4×17):(7,8-17)] = [(60,84-132,6):204]×(68:-9,2) = = (-71,76:204)×(-7,39) = (-0,35)×(-7,39) = 2,59
А1 а)2а^3-14a^2=2a^2*(a-7a)
б)3x^3-2x^2+9x-6=3x(x^2+3)-(2x^2-3)
A3 a)0.16a^4-0.09b^2=(0.4a^2-0.3b)(0.4a^2+0.3b)
в)81с^4+3b^3c=3c(9c^3+b^3)
B1 a)a^2-9b^2-a-3b=(a-3b)(a+3b)-(a+3b)=(a+3b)((a-3b)-1)
б)25c^2-4x^2-4x-1=(5c-2x)(5c+2x)-(4x+1)
17/26*17/6+11/13*17/6=289/156+187/78=(289+374)/156=663/156=17/4=4(1/4)
<span>(x-4)(x+2)-2()3x+1)(x-3)=x(x+27)
</span><span>(x^2+2x-4x-8) - (6x+2)(x-3)= x^2+27x
</span><span>(x^2-2x-8) - (6x^2-18x+2x-6)= x^2 +27x
</span><span>x^2-2x-8 -6x^2+18x-2x+6 = x^2 +27x
</span>x^2-2x<span>-6x^2+18x-2x -x^2-27x= -6+8
</span>-6x^2 -13x= 2
-6x^2-13x-2=0 \*(-1)
6x^2+13x+2=0
D= b^2-4ac= 13^2- 4*6*2= 169- 48= 121
x1,2= (-b +- (корень из)D) / 2*a
x1,2= (-13+-11)/ 12
x1= -2/12= -1/6
x2= -24/12= -2
Ответ: x1= -1/6
x2= -2