1 +1+1+1+1+1+1+1

2+2+2+2+2+2+2+2+2

3 +3x3+3+3x3 x3 +1 =

2 câu trả lời

1x8=8

2x9=18

3x1+3x3+3x1+3x3+1

= 3x( 1+3+1+3)+1

=3x8+1

=24+1=25

 1 +1+1+1+1+1+1+1=8

2+2+2+2+2+2+2+2+2=18

3 +3x3+3+3x3 x3 +1 =43