Если в 1 (а) - то (-8x3)+(12x(-2))=-24-24=-48, а если + то =24-24=0
u-3v=6-(3x(-2))=6+6=12
8z-11t=(8x(-5.5))-(11x(-4))=-44+44+0
5p-4q=(5x(-2/5))-(4x0.5))=-2-2=-4
2)a)a+b+2c=10+(2x7)=24
б)a+b/2-c=10/-5=-2
<span> в) a+b+c/2=10+(7/2)=13.5
</span>г)7x(a+b)+2c/3c-1=70+14/21-1=69 14/21(дробью)
ctgx=1/tgx
tgx≠0
cosx≠0
sinx≠0
6tg²x-4tgx-2=0
3tgx-2tgx-1=0
D=4+12=16
tgx=-1/3 или tgx=1
x=arctg(-1/3)+πk или х=(π/4)+πn, k,n∈Z
О т в е т. arctg(-1/3)+πk ; (π/4)+πn, k,n∈Z
(x+y)^2=x^2+2xy+y^2
4x^2+12x+9=(2x+3)^2
(x-y)(x+y)=x^2-y^2
x^2-y^2=(x-y)(x+y)
x^3-y^3=(x-y_(x^2+xy+y^2)
(p-g)^2=p^2-2pq+q^2
25a^2+10a+1=(5a+1)^2
(4+y^2)(y^2-4)=y^4-16
25x^2-y2=(5x-y)(5x+y)
(-a-2)^2=a^2+4a+4
m^3-n^3=(m-n)(m^2+mn+n^2)
(9-y)^2=81-18y+y^2
b^2+4a^2-4ab=(4a-b)^2
(9a-b^2)(b^2+9a)=81a^2-b^4
(b+3)^2=b^2+6b+9
<span>sin^6(x)+cos^6(x)=(5/4)sin^2(2x)
</span>sin^6(x)+cos^6(x) = 5 sin^2(x)*cos^2(x)
(sin^2(x)+cos^2(x))(sin^4(x)+cos^4(x)-sin^2(x)cos^2(x)) = 5/4sin^2(2x)
1/8(3cos(4x)+5) = -5/8(cos(4x)-1)
<span>cos(4x) = 0
</span>x = πn-(7π)/8
x <span>= πn-(5π)/8
</span>x = πn-(3π)/8
<span>x = πn-π/8</span>
n ∈ Z