Question

Biết:       (a + 1) + (a + 2) + (a + 3) + (a + 4) + (a + 5) = 115
Vậy         a = 

Answer 1

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

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

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

5a+15=115

5a=115-15

5a=100

a=100:5

a=20

Tik Nha !!!

Answer 2

Ta có:(a+1)+(a+2)+(a+3)+(a+4)+(a+5)=115

=ax5+(1+2+3+4+5)=115

=ax5+15=115

=ax5=115-15

=ax5=100

=a   =100:5

=a   =20