第19页

信息发布者:
=19.42
=4.56
=41.54



=11.4
=4.6


$17.7776$
$17.\underbrace{77\cdots7}_{9个7}6$
​$ 6×6 + 4×4 - (6 + 4)×6\div 2 = 22(\mathrm {cm}^2)$​
​$ 16×16\div 2 - 16×9\div 2 = 56(\mathrm {m^2})$​

$-0.05$
$+0.12$