Răspuns :
^ inseamna la putere
d) 9+6x-6x-4x^2+5x^2=9+x^2
e) 25x^2+49-35x+35x-25x^2=49
d) 9+6x-6x-4x^2+5x^2=9+x^2
e) 25x^2+49-35x+35x-25x^2=49
Vom folosi formula (a-b)(a+b)=a²-b²
d) (3-2x)(3+2x)+5x²=
=9-4x²+5x²=
=9+x²
e)25x²+(7+5x)(7-5x)=
=25x²+49-25x²=
=49
d) (3-2x)(3+2x)+5x²=
=9-4x²+5x²=
=9+x²
e)25x²+(7+5x)(7-5x)=
=25x²+49-25x²=
=49