- 4 p ( 8p + 6g) + 3g(8p- 3 g) = - 32 p^2 - 24 pg + 24 pg - 9g^2= - 32p^2 - 9 g^2 =
= - ( 32p^2 +9g^2) = - ( 32 ( 1/2)^2 + 9 ( 1/3)^2 ) = - ( 32 * 1/4 + 9 * 1/9)=
= - (8+1)= - 9
Ответ:
ma+mb-5a-5b=m(a+b)×5(a-b);6m+6n-4m-4n=6(m+n)×4(m-n);3x+5y+15+xy=3(x+1)×5(y+3);7m-8n+14m-4n=7(m-2m)×n(8-4).
2sinx(cosx+sinx)=(cosx-sinx)(cosx+sinx)
cosx=-sinx tgx=-1 x=-П/4+Пn
2sinx=cosx-sinx
3sinx=cosx
tgx=1/3
x=arctg(1/3)+Пn
3sinx+cosx=1
6sinx/2*cosx/2=2sin^2(x/2)
sinx/2=0
x=2Пn
3cosx/2=sinx/2
tgx/2=3
x=2arctg(3)+2Пn
1) -2.3/0.4x+8<0
8-5.75x<0
5.75x<8
x<1.3913
2)-3.8/3.2-6.4x>0
<span>
-6.4x>1.1875
x></span>0.186