Question

Ajutorr plizzz!!!Rezolvati urmatoarele exzercitii :
a) (x-2)(x+2)+(x-3)(x+3)+(x-4)(x+4)+(x-5)(x+5)
b) (a-3)(a+3)+(a-3)la a doua
c)(m+5)la a doua -(m+5)(m-5)

Answer 1

a) x^2-4+x^2-9+x^2-16+x^2-25=4x^2-54
b) a^2-9+a^2-6a+9=2a^2-6a
c)m^2+10m+25-m^2+25=50+10m

Answer 2

a)  (x-2)(x+2)+(x-3)(x+3)+(x-4)(x+4)+(x-5)(x+5)= x²-4+x²-9+x²-16+x²-25=
3x²-54 ( fiecare paranteza are o formula de calcul se asceea am facut asa formula este a²-b²=(a-b)(a+b)
b) (a-3)(a+3)+(a-3)²=a²-9+a²-6a+9= 2a²-6a ( la prima paranteza e aceasi formula dar la adoua e formula asta : (a-b)² =a²-2ab+b²
c)(m+5)²-(m+5)(m-5)= m²+10m+25-m²-25= 10m ( (a+b)²= a²+2ab+b² o alta formula aplicata la prima paranteza, se simplifica m² cu -m² si 25 cu -25 )
SPER CA TE-AM AJUTAT