Distributivité, double distributivité et identités remarquables.....
E = (x+1)² + 7x(2-x)
= x²+2x+1+14x-7x²
= -6x²+16x+1
F = (x+3)(2x-1)-3x(2x+5)
= 2x²-x+6x-3-6x²-15x
= -4x²-10x-3
G = (4t+1)(4t-1)-(3t+2)²
= (4t)²-1²-(9t²+12t+4)
= 16t²-9t²-1-12t-4
= 7t²-12t-5
H = 2(s+5)(s-5)+(4s+3)²
= 2(s²-25)+(16s²+24s+9)
= 2s²+16s²-50+24s+9
= 18s²+24s-41
