Bonjour,
a)[tex]7\left(2x-1\right) = 8x+5\\ 14x-7 = 8x+5\\ 14x-8x = 5+7\\ 6x = 12\\ x = \frac {12}{6} = 2[/tex]
b)[tex]8a-2 = 3\left(4a-5\right)\\ 8a-2 = 12a-15\\ 15-2 = 12a-8a\\ 4a = 13\\ a = \frac{13}{4}[/tex]
c)[tex]2\left(3b+7\right) = 5\left(-2b+1\right)\\ 6b+14 = -10b+5\\ 6b+10b = 5-14\\ 16b = -9\\ b = -\frac{9}{16}[/tex]
d)[tex]3\left(-1-2t\right) = 4\left(1-5t\right)\\ -3-6t = 4-20t\\ 20t-6t = 4+3\\ 14t = 7\\ t = \frac{7}{14} = \frac 12[/tex]
