2x(3+5)=2x-(2+7x)
6x + 10x = 2x -2 -7x
6x+10x-2x+7x = -2
21x = -2
x= -2/21(ułamek)
3x(2+3)=3(7x+2)
6x + 9x = 21x + 6
6x +9x -21x = 6
15x -21x =6
-6x = 6
x = -1
10(5x+3)=(x+2)(x+2)
50x + 30 = x² + 2x + 2x + 4
50x-2x-2x - x²= 4
46x - x² = 4
2x-(3x+2)=7-(7x+7)
2x -3x -2 = 7 - 7x - 7
2x - 3x + 7x = 7 - 7 +2
6x = 2
x = 2/6 = 1/3