Question

17．若$\sqrt{2a+^{2}}$+|b²-10|=0，求ab的值．

Answer 1

分析 根據(jù)非負(fù)數(shù)的性質(zhì)列出方程求出a、b的值，代入所求代數(shù)式計(jì)算即可．

解答 解：根據(jù)題意得：$\left\{\begin{array}{l}{2a+^{2}=0}\\{^{2}-10=0}\end{array}\right.$，
解得：$\left\{\begin{array}{l}{a=-5}\\{b=\sqrt{10}}\end{array}\right.$或$\left\{\begin{array}{l}{a=5}\\{b=-\sqrt{10}}\end{array}\right.$．
則ab=±5$\sqrt{10}$．

點(diǎn)評(píng) 本題考查了非負(fù)數(shù)的性質(zhì)：幾個(gè)非負(fù)數(shù)的和為0時(shí)，這幾個(gè)非負(fù)數(shù)都為0．