Question

(2x+3)² - x² = 144

solve this problem plz


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Answer 1

$\huge{ \boxed{ \fcolorbox{cyan}{pink}{Answer}}}$

$\; \; \;$

$\bold \orange{ : \longmapsto \: {(2x + 3)}^{2} - {x}^{2} = 144}$

$\bold \purple{ : \longmapsto \: (2x + 3 + x)(2x + 3 - x) = 144}$

$\bold \orange{ : \longmapsto \: (3x + 3 )(x + 3) = 144}$

$\bold \purple{ : \longmapsto \: (x + 1)(x + 3) = 48}$

$\bold \orange{ : \longmapsto \: (x + 1)(x + 3) = (5 + 1)(5 + 3)}$

$\bold \purple{ : \longmapsto \: x \: = 5}$

$\; \; \;$

$\boxed{ \fcolorbox{cyan}{black}{ \boxed{\bold \pink{ \boxed{ \fcolorbox{cyan}{orange}{ \boxed{\bold \purple{Answer : x = 5}}}}}}}}$

Answer 2

Use ( a + b ) ( a - b )

( 2x + 3 - x ) ( 2x + 3 + x )
( x + 3 ) ( 3x + 3) = 144
3x2 + 12x -135 = 0
x2 + 4x -45 = 0
x2 + 9x -5x -45 = 0
( x + 9) ( x-5 ) = 0

x = -9 or +5