Đáp án:
B6:
5) x=0
Giải thích các bước giải:
\(\begin{array}{l}
B5:\\
1)x + 8 - x - 22 = 8 - 22 = - 14\\
2) - x - a + 12 + a = - x + 12\\
Thay:x = - 98\\
\to - \left( { - 98} \right) + 12 = 110\\
Thay:x = 99\\
- 99 + 12 = - 87\\
3)a - m + 7 - 8 + m\\
= a - 1\\
Thay:a = 1;m = - 123\\
\to 1 - 1 = 0\\
4)m - 24 - x + 24 + x\\
= m\\
Thay:x = 37;m = 72\\
\to 72 = 72\\
5) - 90 - y - 10 + 100\\
= - y\\
Thay:y = - 24\\
\to - \left( { - 24} \right) = 24\\
B6:\\
1)2x - 5 = - 9\\
\to 2x = - 4\\
\to x = - 2\\
2)2\left( {4 - 3x} \right) = 14\\
\to 4 - 3x = 7\\
\to 3x = - 3\\
\to x = - 1\\
3)3\left( { - x + 7} \right) = - 6\\
\to 7 - x = - 2\\
\to x = 9\\
4)3x - 2 = - 8\\
\to 3x = - 6\\
\to x = - 2\\
5)5\left( { - 3 - 2x} \right) = - 15\\
\to - 3 - 2x = - 3\\
\to x = 0
\end{array}\)
