Đáp án:
m1 = 473g m2 = 157g
Giải thích các bước giải:
Ta có:
\[\begin{array}{l}
D = \frac{m}{V} \Leftrightarrow \frac{{630}}{{90\% .\left( {{V_1} + {V_2}} \right)}} = 7\\
\Leftrightarrow 90\% \left( {{V_1} + {V_2}} \right) = 90 \Rightarrow {V_1} + {V_2} = 100\\
\Leftrightarrow \frac{{{m_1}}}{{{D_1}}} + \frac{{{m_2}}}{{{D_2}}} = 100 \Leftrightarrow \frac{{{m_1}}}{{11,3}} + \frac{{{m_2}}}{{2,7}} = 100\\
\Leftrightarrow 2,7{m_1} + 11,3{m_2} = 3051\left( 1 \right)\\
{m_1} + {m_2} = 630\left( 2 \right)\\
{\kern 1pt} \left( 1 \right),\left( 2 \right) \Rightarrow \left\{ \begin{array}{l}
{m_1} = 473g\\
{m_2} = 157g
\end{array} \right.
\end{array}\]