Question

What is the value of x? Enter your answer in the box. x =

Answer 1

The answer is:  " 11 " .
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            →     " x  =  11  "  .
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Explanation:
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Set up the ratio/ proportion as a fraction:

6 cm / 48 cm = 5 cm / (3x + 7) ; 

→ The "cm" units cancel out; since:  "cm/cm = 1 " ; 

→ The "6/48" = "(6 ÷ 6) / (48 ÷ 6) =  " 1/8 " ; 

→ Rewrite as:  $\frac{1}{8} = \frac{5}{3x + 7}$ ;

Now, we can "cross-multiply" :
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Note:  $Given: \frac{a}{b} = \frac{c}{d}$ ;  $ad = bc$ ; 
              {b$\neq 0$ ;  d $\neq 0$} .
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As such:      
 
    1 * (3x + 7) = 8 * 5 ;

   →  3x + 7 = 40 ; 

Subtract "7" from each side of the equation:

   →  3x + 7 − 7 = 40 − 7 ; 

to get:  

   → 3x = 33 ; 

Now, divide each side of the equation by "3" ; 
   to isolate "x" on one side of the equation; & to solve for "x" ; 

   →  3x / 3 = 33 / 3 ; 

to get: 
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   →    " x = 11 " .
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   →   The answer is:  " 11 " .
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Answer 2

Hey there !

Check the attachment.
Hope it helps