bonjour
B= 2(-3x+5) - (2x+5)(2x-5)
B = ( - 6 x + 10 ) - ( 4 x² - 10 x + 10 x - 25 )
= - 6 x + 10 - 4 x² + 25
= - 4 x² - 6 x + 35
C=(5x-2)(5x-8)-(3x-5)(x+7)
= 25 x² - 40 x - 10 x + 16 - ( 3 x² + 21 x - 5 x - 35 )
= 25 x² - 50 x + 16 - 3 x² - 21 x +5 x + 35
= 22 x² - 66 x + 51
