Ответ:

x =  [tex]-\frac{3}{2}[/tex]

Объяснение:

( 7 - 2x )² - ( 2x - 3 ) · ( 2x + 3 ) = 100,

( 7 - 2x )² - ( 2x · ( 2x + 3 ) - 3 · ( 2x + 3 )) = 100,

( 7 - 2x )² - ( 4x² + 6x - 6x - 9) = 100,

( 7 - 2x )² - 4x² + 9 = 100,

( 7 - 2x ) · ( 7 - 2x ) - 4x² + 9 = 100,

7 · ( 7 - 2x ) - 2x · ( 7 - 2x ) - 4x² + 9 = 100,

49 - 14x - 14x + 4x² - 4x² + 9 = 100,

49 - 14x - 14x + 9 = 100,

58 - 14x - 14x = 100,

- 28x = 100 - 58,

- 28x = 42,

x = 42 : -28,

x = 3 : -2,

x =  [tex]-\frac{3}{2}[/tex] ,