A)13(a-b)+15a(a-b)=(13+15a)(a-b)
б)6(7a-6p)-5p(7a-6p)=(6-5p)(7a-6p)
2)9x(x+1)-14y(x+1)=(9x-14y)(x+1)=
=(9*5/9-14*5/14)(5/9+1)=
=(5-5)*14/9=0*14/9=0
3) 0,85(1/6+1/3)-0,65(1/6+1/3)=
=(0,85-0,65)(1/6+1/3)=0,2*0,5=0,1
1/9a^6=(1/3a^3)^2; 0,16a^4b^10=(0,4a^2b^5)^2.
Смотри )))))))))))))))))))))))))))))
2[x+1]=3x
[x+1]=3x/2
x+1=3x/2
<span>1=x/2
x=2
</span>x+1=-3x/2
1=-2x
x=-1/2
<span>ответ -1/2;2
</span>2.[x^2+3]< 12
x^2+3<12
x^2+3>-12
x^2<9
x<span>∈(-3;3)
</span>
sin110=sin250
cos540=cos(360+180)=cos180=-1
cos290=cos(180+110)=-cos110
cos430=cos(360+70)=cos70
cos70=cos110
(sin ²110+cos ²110)/cos<span> ²(1440+180)
1/cos</span> ²1620=1/cos ²180=1
(х - 3)^2 - 5|х - 3| + 4 ≤ 0
(x - 3)^2 = |x - 3|^2
|x - 3| = t ≥ 0
t^2 - 5t + 4 ≤ 0
D = 25 - 16 = 9 = 3^2
t12 = (5 +- 3)/2 = 1 4
(t - 1)(t - 4) ≤ 0
++++++++[1] ------------- [4] +++++++++++
1 ≤ t ≤ 4
1. |x - 3| ≥ 1
x - 3 ≥ 1 x ≥ 4
x - 3 ≤ -1 x ≤ 2
x ∈ (-∞,2] U [4, +∞)
2. |x - 3| ≤ 4
x - 3 ≤ 4 x ≤ 7
x - 3 ≥ -4 x ≥ -1
x ∈ [-1, 7]
пересекаем с первым вариантом
ответ х ∈ [-1, 2] U [4,7]