linouchette Bonjour

1.
f (x)=(4x-5)^2+(4x-5)(12x+1)
f (x)=16x^2-2×4x×5+25+48x^2+4x-60x-5
f (x)=256-40x+25+48x^2+4x-60x-5
f (x)=48x^2-100x+281
2.
f (x)=(4x-5)(4x-5+12x+1)
f (x)=(4x-5)(16x-4)
f (x)=4 (4x-5)(4x-1)
f (0)=4 (0-5)(0-1)
f (0)=20

f (5/4)=4 (4×5/4-5)(4×5/4x-1)
f (5/4)=4 (5-5)(5x-1)
f (5/4)=0

bouv 1.(4x-2)²+(4x-5)(12x+1)
   =(4x)²-2x4Xx5+5²+(4x-5)(12x+1)
   =16x²-40x+25+48x²+4x-60x-5
    =64x²-96x+20
2.(4x-5)²+(4x-5)(12x+1)
  =(4x-5)[(12x+1)+(4x-5)]
   =(4x-5)[12x+1+4x-5]
   =(4x-5)(16x-4)