1) x(a^2-b^2)=a(a+b)
x=(a(a+b))/(a-b)(a+b)
x=a/(a-b)
3) xa(a^3-1)=2a(a-1)(a^2+
+a+1)
xa= (2a(a^3-1))/(a^3-1)
xa=2a, x=2a/a, x=2
5) ab^2(2a-3b)= -x(2a-3b)*
*a^2b
-x=(ab^2(2a-3b))/(a^2b(2a-3b)
-x=b/a, x= -b/a
1) 12sin150*cos120 = 12sin(180-30) * cos(90+30) = 12*sin30 * (-sin30)= -12*1/2 * 1/2 = -3
2) 44sin44*cos44 / sin88 = 22sin88 / sin88 = 22
3) (cos²44 + cos²46) / 2 = (cos²(90-46) + cos²46) / 2 = (sin²46 + cos²46) / 2 =1/2
4) cosα = 15/17
sinα = - √(1-225/289) = - √(64/289) = - 8/17
34sinα = 34*(-8/17) = -16
(2х +1)(х-3) = 2(х^2 + х + 9)
2х^2 - 6х + х - 3 = 2х^2 + 2х + 18
-6х + х - 3 = 2х +18
- 5х - 3 = 2х + 18
-5х - 2х = 18 + 3
-7х = 21 | ÷ ( - 7)
х = - 3
Ответ: -3