Bonjour,
Ex47
A=(x²+2)²=x⁴+4x²+4
B=(2x+1)²+(2x-1)²-8x²=4x²+4x+1+4x²-4x+1-8x²=8x²+2-8x²=2
C=2(3t-5)²-2(1-4t)²=2(9t²-30t+25)-2(1-8t+16t²)=18t²-60t+50-2+16t-32t²
C=-16t²-44t+48
D=(1+4y)²-(2y+3)²-(1+4y)(2y+3)
D=(1+8y+16y²)-(4y²+12y+9)-(2y+3+8y²+12y)
D=1+8y+16y²-4y²-12y-9-2y-3-8y²-12y=4y²-16y-11
Ex48
E=(2x+1)²+(2x+1)=(2x+1)(2x+1+1)=(2x+1)(2x+2)=2(2x+1)(x+1)
F=3(2x-3)²-(2x-3)=(2x-3)(3(2x-3)-1)=(2x-3)(6x-10)=2(2x-3)(3x-5)
G=(x+4)(3x+4)-x-4=(x+4)(3x4)-(x+4)=(x+4)(3x+4-1)=3(x+4)(x+1)
H=(3x+7)(2x+1)+(x-4)(-2x-1)=(2x+1)(3x+7-(x-4))=(2x+1)(2x+11)
