Question

Образец:a^2+6a+9=a^2+2*3*a+3^2=(a+3)^2

a)49p^2-42p+9=

б)4m^2+20m+25=

Answer 1

$49p^2-42p+9=(7p)^2-2*7p*3+3^2=(7p-3)^2$

 

$4m^2+20m+25=(2m)^2+2*2m*5+5^2=(2m+5)^2$