Đáp án:
b) \(\left[ \begin{array}{l}
x = 3\\
x = - 2
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a)2.\left( {x - 3} \right) = - x - 18\\
\to 2x - 6 = - x - 18\\
\to 3x = - 12\\
\to x = - 4\\
b)\left( {x - 3} \right)\left( {2y + 4} \right) = 0\\
\to \left[ \begin{array}{l}
x - 3 = 0\\
2y + 4 = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 3\\
x = - 2
\end{array} \right.\\
c)54 \times \left( { - 46} \right) + ( - 46 \times 16 + 70 \times \left( { - 54} \right))\\
= - 54.46 - 46.16 - 54.70\\
= 46\left( { - 54 - 16} \right) - 54.70\\
= 46.\left( { - 70} \right) - 54.70\\
= 70\left( { - 46 - 54} \right)\\
= 70.\left( { - 100} \right) = - 7000\\
d)( - 52) \times 38 - 38 \times 34 + 86 \times 68\\
= - 52.38 - 38.34 + 86.68\\
= 38.\left( { - 52 - 34} \right) + 86.68\\
= - 86.38 + 86.68\\
= 86\left( {38 + 68} \right)\\
= 86.106 = 9116\\
e)156 - 56 \times 46 + \left( { - 54} \right) \times 56\\
= 56\left( { - 46 - 54} \right) + 156\\
= - 100.56 + 156\\
= - 5600 + 156\\
= - 5444
\end{array}\)
