Toán (3.|x|-2 mũ 4 ).7 ³=2.7 mũ 4 AI NHANH NHẤT MIK SẼ CHO TLHN 15/11/2021 By Jade (3.|x|-2 mũ 4 ).7 ³=2.7 mũ 4 AI NHANH NHẤT MIK SẼ CHO TLHN
$(3|x|-2^4).7^3=2.7^4$ $(3|x|-16).7^3=2.7^4$ $3|x|-16=2.7^4:7^3$ $3|x|-16=14$ $3|x|=14+16$ $3|x|=30$ $|x|=30:3$ $|x|=10$ \(\left[ \begin{array}{l}x=10\\x=-10\end{array} \right.\) Trả lời
( 3 . | x | – 2^4 ) . 7^3 = 2 . 7^4 ⇔ 3 . | x | – 16 = 2 . 7^4 : 7^3 ⇔ 3 . | x | – 16 = 2 . ( 7^4 : 7^3 ) ⇔ 3 . | x | – 16 = 2 . 7 ⇔ 3 . | x | – 16 = 14 ⇔ 3 . | x | = 14 + 16 ⇔ 3 . | x | = 30 ⇔ | x | = 30 : 3 ⇔ | x | = 10 ⇔ \(\left[ \begin{array}{l}x = 10\\x = -10\end{array} \right.\) Vậy , x ∈ { 10 ; – 10 } Trả lời
$(3|x|-2^4).7^3=2.7^4$
$(3|x|-16).7^3=2.7^4$
$3|x|-16=2.7^4:7^3$
$3|x|-16=14$
$3|x|=14+16$
$3|x|=30$
$|x|=30:3$
$|x|=10$
\(\left[ \begin{array}{l}x=10\\x=-10\end{array} \right.\)
( 3 . | x | – 2^4 ) . 7^3 = 2 . 7^4
⇔ 3 . | x | – 16 = 2 . 7^4 : 7^3
⇔ 3 . | x | – 16 = 2 . ( 7^4 : 7^3 )
⇔ 3 . | x | – 16 = 2 . 7
⇔ 3 . | x | – 16 = 14
⇔ 3 . | x | = 14 + 16
⇔ 3 . | x | = 30
⇔ | x | = 30 : 3
⇔ | x | = 10
⇔ \(\left[ \begin{array}{l}x = 10\\x = -10\end{array} \right.\)
Vậy , x ∈ { 10 ; – 10 }