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a. 14 x-7=8x+5

6x/6=12/6

x=2

 

b. 8a-2=3*(4a-5)

8a-2=12a-15

-4a/-4=-13/-4

a=3.25

 

c.2*(3b+7)=5*(-2b+1)

6b+14=-10b+5

16b/16=-9/16

b=-9/16

 

d. 3*(-1-2t)=4*(1-5t)

-3-6t=4-20t

14t/14=7/14

t=1/2

xxx102

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]

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