Question

if (x-9) : (3x+7) is a duplicate ratio of 4:9 ,find x

Answer 1

Hola User!!

Your answer :-


$= > \frac{(x - 9)}{(3x + 7)} = \frac{4}{9} \\ \\ by \: cross \: multiplication \\ \\ = > 9(x - 9) = 4(3x + 7) \\ \\ = > 9x - 81 = 12x + 28 \\ \\ = > 9x - 12x = 28 + 81 \\ \\ = > - 3x = 109 \\ \\ = > x = \frac{109}{ - 3} \\ \\ = > x = \frac{ - 109}{3}$

Hope it helps!!

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Answer 2

Hey ❗

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↪x - 9 / 3 x + 7 = 4 / 9

↪By cross - multiplying !!

↪We get ,

↪( x - 9 ) ( 9 ) = 3x + 7 ( 4 )

↪9 x - 81 = 12x + 28

↪9x - 12x = 28 + 81

↪- 3x = 109

↪x = - 109 / 3

↪Or if the equation is

↪x - 9 / 3x + 6 = 4 / 9

↪Again by cross multiplying !!

↪( x - 9 ) ( 9 ) = ( 3x + 6 ) ( 4 )

↪9x - 81 = 12x + 24

↪9x - 12x = 24 + 81

↪- 3x = 105

↪x = - 105 / 3

↪x = - 35

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