Question

(1/3+1/5)×15=?(1/9+1/3)×27=?(1/6+1/4)×36=?89×7/88=?要简便运算,

Answer 1

(1/3+1/5)×15

=1/3×15+1/5×15

=5+3

=8

(1/9+1/3)×27

=1/9×27+1/3×27

=3+9

=12

(1/6+1/4)×36

=1/6×36+1/4×36

=6+9

=15

89×7/88

=(88+1)×7/88

=7+7/88

=7又7/88