Mn giải hộ e mấy bài này nhé ! d)|x-15| = 5 E) (12x -30) : 6 + 59 = 8^2 F) 12-(-54 + 2x) = 90

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!!!