Đáp án:
$d)|x-15| = 5$
$⇔$ \(\left[ \begin{array}{l}x-15=5\\x-15=-5\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x=5+15\\x=-5+15\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x=20\\x=10\end{array} \right.\)
$e) (12x -30) : 6 + 59 = 8²$
$⇔ (12x-30):6+59=64$
$⇔ (12x-30):6=64-59$
$⇔ (12x-30):6=5$
$⇔ 12x-30=5.6$
$⇔ 12x-30=30$
$⇔ 12x=30+30$
$⇔ 12x=60$
$⇔ x=5$
$F) 12-(-54 + 2x) = 90$
$⇔-54+2x=12-90$
$⇔ -54+2x=-78$
$⇔ 2x=-78-(-54)$
$⇔ 2x=-24$
$⇔ x=-12$
BẠN THAM KHẢO NHA!!!
