1)
[tex]2d - 4 = -d - 5\\\\2d+d = -5+4\\\\3d = -1 \ \ /:3\\\\\boxed{d =-\frac{1}{3}}[/tex]
2)
[tex]-3x+2 = 7 + 4x\\\\-3x-4x = 7 - 2\\\\-7x = 5 \ \ /:(-7)\\\\\boxed{x = -\frac{5}{7}}[/tex]
3)
[tex]r + 6 = 2r + 7\\\\r - 2r = 7-6\\\\-r = 1 \ \ /:(-1)\\\\\boxed{r = -1}[/tex]
4)
[tex]5t - 6 = 3t - 10\\\\5t - 3t = -10+6\\\\2t = -4 \ \ /:2\\\\\boxed{t = -2}[/tex]
