3(а+5)^2-3а^2 помогите

Question

3(а+5)^2-3а^2 помогите

Answer 1

3(a+5)²-3a²=3(a²+10a+25)-3a²=3a²+30a+75-3a²=30a+75

Answer 2

3(а^2+10а+25)-3а^2=3а^2+30а+75-3а^2=30а+75