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 Apr 1, 2020
 #1
avatar+23695 
+1

 B = 3x+8     we want 3 times this    3 (3x+8) = 9x + 24     equal to A  = 5x-4

 

9x+24 = 5x -4

4x = -28

x = -7 

 Apr 1, 2020
 #2
avatar+21013 
+1

For machne A:  with an input of  x  its output will be 5x - 4

For machine B: with an input of  x  its output will be 3x + 8

 

If machine A's output is three times machine B's output:  5x - 4  =  3(3x + 8)

                                                                                           5x - 4  =  9x + 24

               subtract 5x from both sides:                                      -4  =  4x + 24

               subtract 24 from both sides:                                    -28  =  4x

               divide both sides by 4:                                               -7  =  x

 

Checking:  machine A:  5x - 4  =  5(-7) - 4  =  -35 - 4  =  -39

                  machine B:  3x + 8  =  3(-7) + 8  =  -21 + 8  =  -13

And:  -39 is three times -13.

 Apr 1, 2020
 #3
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0

thnk you so much

 Apr 1, 2020

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