Respuesta :

m*m+m*7+3*m+3*7
Answer= 
m^2+10m+21

Answer:

m² + 10m + 21

Step-by-step explanation:

(m + 3)(m + 7)

m(m + 7) + 3(m + 7)

m² + 7m + 3m + 21

m² + 10m + 21

RELAXING NOICE
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