Question

calcule a soma da diferença de dois produtos 
ME DE A RESPOSTA CONCRETA !!!!
(m-1).(m+1)

(2-7x).(2+7x)

(m-5).(m+5)

(3x+5)(3x-5)

Obrigada (:

Answer 1

$(m-1).(m+1)=m^2-1^2=m^2-1\\\\ (2-7x).(2+7x)=2^2-(7x)^2=4-49x^2\\\\ (m-5).(m+5)=m^2-5^2=m^2-25\\\\ (3x+5)(3x-5)=(3x)^2-5^2=9x^2-25$