Question

[Nguyễn Việt Anh]

Bài 2: Tính nhanh a/ A = + + + 1522 393 1478 607 e/ E = + + 38.56 7.8.45 17.56 b/ B = + + + + 251 849 759 231 141 f/ F = + + + 49.15 75.49 49.25 15.51 c/ C = + + + + 2004 2005 2006 2007 2008 g/ G = + + 12.45 9.4.19 72.83 d/ D = 75.125.32 

Answer 1

[Athanasia Karrywang]

$a)17.85+15.17-120$

$\iff 1445+15.17-120$

$\iff 1445+255-120$

$\iff 1580$

$b)2³.17-2³.14$

$\iff 8.17-8.14$ $\iff 136-8.14$

$\iff 24$ $c)20-[30-(5-1)²:2]$

$\iff 20-(30-4{}^{}:2)$

$\iff 20-(30-8)$

$\iff -2$

$d)80-(4.5²-3.2²)$

$\iff 80-(4.25-3.22)$

$\iff 80-(100-12)$

$\iff -8$

e) $27.77+24.27-27$

$\iff 27.77+24.27-27.1$

$\iff 27.(77+24-1)$

$\iff 27$

$g)174:\{2.[36+(4²-23)]\}$

$\iff 174:\{2\cdot [36+(16-23)]\}$

$\iff 174:\{2\cdot [36-7]\}$

$\iff 174:\{2\cdot 29\}$

$\iff 174:58$

$\iff 3$