Question

( x + 7 ) . ( x - 4 ) + ( 5x - 1 )² + 3( x + 2 )² - ( x - 3 ) . ( x + 3 ) =

Answer 1

( x + 7 ) . ( x - 4 ) + ( 5x - 1 )² + 3( x + 2 )² - ( x - 3 ) . ( x + 3 )

x² - 4x + 7x - 28 + (5x - 1).(5x - 1) + 3.(x+2).(x+2) - (x² + 3x- 3x - 9)

x² - 4x+ 7x - 28 + (25x² - 5x - 5x + 1) + 3.(x²+2x+2x+4) -  x² - 3x+3x +9

x² - 4x+ 7x - 28 + (25x² - 10x + 1) + 3.(x² + 4x + 4)  -  x² - 3x+ 3x + 9

x² - 4x+ 7x - 28 + 25x² - 10x + 1 + 3x² + 12x + 12 -  x² - 3x+ 3x+ 9

x² + 25x² + 3x² - x² - 4x - 10x- 3x+ 7x+ 12x+ 3x - 28 + 9 + 1+ 12

29x² - x² - 17x + 22x - 28 + 22

28x² + 5x - 6