Question

Efectuati calculele:
a) (x-2)(x+2)+(x-3)(x+3)+(x-4)(x+4)+(x-5)(x+5)=

b)(a-3)(a+3)+(a-3)²=

c)(m+5)²-(m+5)(m-5)=

Answer 1

a)⇒ x²-4+x²-9+x²-16+x²-25⇒4x²+54   =2(2x²+27)
b)=a²-9+a-6a+9=a²-5a=a(a-5)
c)=m²+10m+25-m²+25=10m+50=10(m+5)