2x + 3x - 5x = 5x - 5x = 0
2x²-12x-59<-3x²-5x-25
2x²+3x²-12x+5x-59+25<0
5x²-7x-24<0
D=49+480=529
x=(7+-23)/10
x1=(7+23)/10=30/10=3
x2=(7-23)/10=-16/10=-1,6
Ответ: (-1,6:3)
| 7x - 2 | = 0
(7x - 2) = 0
7x = 2
x = 2/7
Ответ: 2/7
36-x²=64-(10-x²)
36-x²=64-10+x²
36-x²=54+x²
-x²-x²=54-36
-2x²=18
x²=-9
x=<span>±</span>√-9
x∉R
sin2a=-2sinacosa=-2*0,8*0,6=-0,96