Đáp án:
 
Giải thích các bước giải:
$a,5.2^2-18:3^2$
$=5.4-18:9$
$=20-2=18$
$b,75-(3.5^2-4.2^3)$
$=75-3.25+4.8$
$=75-75+32$
$=32$
$c,(6^{2007}-6^{2006}):6^{2006}$
$=\dfrac{6^{2007}-6^{2006}}{6^{2006}}$
$=\dfrac{6^{2006}(6-1)}{6^{2006}}$
$=6-1=5$
$d,2.[(7-3^3.3^2):2+99]-100$
$=2.[(7-27.9):2+99]-100$
$=2.[-118+99]-100$
$=2.(-19)-100$
$=-38-100$
$=-138$
$e,(7^{2005}-7^{2004}):7^{2004}$
$=\dfrac{7^{2005}-7^{2004}}{7^{2004}}$
$=\dfrac{7^{2004}(5-1)}{7^{2004}}$
$=5-1=4$
$f,2^3-5^3:5^2+12.2^2$
$=8-5+12.4$
$=3+48=51$