Sagot :
A = (2x-3)(-x+5)-(x+4)(-3x+2)
A = - 2x² + 10x + 3x - 15 + 3x² - 2x + 12x - 8
A = x² + 23x - 23
A= ( -2xcarré+10x+3x-15)-(-3xcarré+2x-12x+8)
A= -2xcarré+10x+3x-15+3xcarré-2x+12x-8
A=xcarré+23x-23
A= -2xcarré+10x+3x-15+3xcarré-2x+12x-8
A=xcarré+23x-23