(7x-8)^2-(3x+5)^2 trbbb cu formulaa a^2 -b^2 va roggggg

Răspuns :

(7x-8)²-(3x+5)²=
49x²-72x+64-9x²-30x-25⇒
40x²-102x+39
succes
=(7x-8-3x-5)(7x-8+3x+5)=(4x-13)(10x-3)

cand am aplicat formula  am luat   a=7x-8  iar b=3x+5