my name is phuong . Today, I want to write about my school . It is DVN lower secondary school. I think it is very wonderful l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l ll l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l ll l l l l l l l l l l l l l . I love my school so much

(a+1)+(a+2)+(a+3)+(a+4)+(a+5)=115

=> a.5 + 1 + 2 + 3 + 4 + 5 = 115

=>a.5 + 15 = 115

=> a.5 = 100 

=> a =20