1. 3х(х-7)-х(4+3х)=5
3х²-21х-4x-3x²-5
-25x-5
x=5
2. 5х-х²+3=х(2-х)
5х-х²+3=2x-x²
5x-x²+3-2x+x²
3x=3
x=1
1. -1/5
2. -1
Объяснение:
1. 3x ( x - 7) - x ( 4 + 3x) = 5
3x² - 21x - 4x - 3x² = 5
- 25x = 5
2. 5x - x² + 3 = x ( 2 - x)
5x - x² + 3 = 2x - x²
5x + 3 = 2x
5x - 2x = -3
3x = -3
x = -1
