Sagot :
(3x+4)²+(2x-7)(x+3)= (9x² + 2*4*3x +16) + (2x² + 6x -7x -21) = 9x²+24x+16 + 2x²-1x-21 = 11x² +23x -5
1. 9x^2+24x+16+2x^2+6x-7x-21
11x^2+23x-5
2. 81x^2-72x+16-(49x^2-35x+35x-25)
81x^2-72x+16-49x^2+35x-35x+25
32x^2-72x+41
11x^2+23x-5
2. 81x^2-72x+16-(49x^2-35x+35x-25)
81x^2-72x+16-49x^2+35x-35x+25
32x^2-72x+41