Question

упростите выражение 3(у+5)^2-3y^2

Answer 1

$3(y+5)^{2}-3y^{2}=3(y^{2}+10y+25)-3y^{2}=3y^{2}+30y+75-3y^{2}=(3y^{2}-3y^{2})+30y+75= 30y+75$

Answer 2

3*(y^2+5y+5y+25)-3y^2=3y^2+15y+15y+75-3y^2=30y+75