Question

Dau coronița de la 1,3,5,7,9,11,13 VA ROG MULT AJUTOR

Answer 1

1. 2( 3x + 1 ) + 3( 1 - 2x ) = 6x + 2 + 3 - 6x = 2 + 3 = 5

3. x × x + x + x : x = x² + x + 1

5. x⁸ : x⁷ + x⁶ : x⁵ - x⁴ : x³ + x² : x = x + x + x + x = 4x

7. ( x - 2 )( x + 2 ) + 4 = ( a - b )( a + b ) = a² - b² = x² - 4 + 4 = x²

9. ( x + 4 )( x - 3 ) - x + 12 = x² - 3x + 4x - 12 - x + 12 = x² - 3x + 4x - x = x²

11. ( 2x + 1 )² - ( 2x - 1 )² = ( a - b )( a + b ) = a² - b² = 2 × 4x = 8x

13. ( x² + x + 1 )² - ( x² + x )² = ( a - b )( a + b ) = a² - b² = 1( 2x² + 2x + 1 )