bonjour

A =  6 x² - 4 x - x + 7

A = 6 x² - 5 x + 7

B  = 6 x + 4 + 3 x - 7

B =  9 x - 3

C = 2 x - 8 + 3 x - 9

C = 5 x - 17

Bonjour,

A = 2x(3x-2)-(x-7) = 2x*3x-2x*2-x+7

                            = 6x²-5x+7

B = (6x+4)+(3x-7) = 6x+3x+4-7 = 9x-3

C = (2x-8)-(-3x+9) = 2x+3x-8-9 = 5x-17