Réponses

2013-10-10T20:21:19+02:00
A=16(2x-3)² -9(4x+1)² =16(4x²-12x+9)-9(16x²+8x+1)=64x²-192x+144-144x²-72x-9= -80x²-264x+155

B= 49-25x² -6(7-5x)²=49-25x²-6(49-70x+25x²)=49-25x²-294+420x-150x²= -175x²+420x-245