(x+5)^3-3=-67 11-(2x-3)^2=2 Question (x+5)^3-3=-67 11-(2x-3)^2=2 in progress 0 Môn Toán Doris 1 year 2020-11-27T03:09:46+00:00 2020-11-27T03:09:46+00:00 2 Answers 41 views 0
Answers ( )
Giải thích các bước giải:
a) $(x+5)^3-3=-67$
$=>(x+5)^3=-64$
$=>x+5=-4$
$=>x=-9$
b) $11-(2x-3)^2=2$
$=>(2x-3)^2=9$
Th1: $2x-3=3$
$=>2x=6$
$=>x=3$
Th2: $2x-3=-3$
$=>2x=0$
$=>x=0$
Đáp án:
$(x + 5)³ – 3 = – 67$
$⇔ (x + 5)³ = – 67 + 3$
$⇔ (x + 5)³ = – 64$
$⇔ (x + 5)³ = ( – 4)³$
$⇔ x + 5 = – 4$
$⇔ x = – 9$
$11 – (2x – 3)² = 2$
$⇔ (2x – 3)² = 11 – 2$
$⇔ (2x – 3)² = 9$
$⇔$ \(\left[ \begin{array}{l}(2x-3)²=3²\\(2x-3)² = (-3)²\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}2x-3=3\\2x-3=-3\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x=3\\x=0\end{array} \right.\)