a, 2x – 15 = -47 b, $(-5)^{2}$ – (5x – 3 = 43 c, ( x – 3)(2x + 6) = 0 01/11/2021 Bởi Josie a, 2x – 15 = -47 b, $(-5)^{2}$ – (5x – 3 = 43 c, ( x – 3)(2x + 6) = 0
Đáp án: Giải thích các bước giải: $2x-15=-47$ $⇒2x=-32$ $x=-16$ $ $ $(-5)^{2}-(5x-3)=43$ $25-5x+3=43$ $25-5x=40$ $5x=-15$ $x=-3$ $ $ $(x-3)(2x+6)=0$ $⇒$$\left \{ {{x-3=0} \atop {2x+6=0}} \right.$ ⇒$\left \{ {{x=3} \atop {x=-3}} \right.$ Bình luận
Đáp án: $\text{a) 2x-15 = -47}$ $\text{<=> 2x = -47 + 15}$ $\text{<=>2x = -32}$ $\text{<=> x = -32 : 2}$ $\text{<=> x = -16}$ $\text{Vậy x = {-16} }$ $\text{b) (-5)² – (5x-3) = 43}$ $\text{<=> 25 – 5x + 3 =43}$ $\text{<=> -5x = 43 -3 – 25}$ $\text{<=> -5x = 15}$ $\text{<=> x = 15 : (-5)}$ $\text{<=> x = -3}$ $\text{Vây x = {-3}}$ $\text{c) (x-3)(2x+6) =0}$ $\text{<=>\(\left[ \begin{array}{l}x-3=0\\2x+6=0\end{array} \right.\) }$ $\text{<=> \(\left[ \begin{array}{l}x=3\\x=-3\end{array} \right.\) }$ $\text{Vậy x = { 3 ;-3} }$ Bình luận
Đáp án:
Giải thích các bước giải:
$2x-15=-47$
$⇒2x=-32$
$x=-16$
$ $
$(-5)^{2}-(5x-3)=43$
$25-5x+3=43$
$25-5x=40$
$5x=-15$
$x=-3$
$ $
$(x-3)(2x+6)=0$
$⇒$$\left \{ {{x-3=0} \atop {2x+6=0}} \right.$ ⇒$\left \{ {{x=3} \atop {x=-3}} \right.$
Đáp án:
$\text{a) 2x-15 = -47}$
$\text{<=> 2x = -47 + 15}$
$\text{<=>2x = -32}$
$\text{<=> x = -32 : 2}$
$\text{<=> x = -16}$
$\text{Vậy x = {-16} }$
$\text{b) (-5)² – (5x-3) = 43}$
$\text{<=> 25 – 5x + 3 =43}$
$\text{<=> -5x = 43 -3 – 25}$
$\text{<=> -5x = 15}$
$\text{<=> x = 15 : (-5)}$
$\text{<=> x = -3}$
$\text{Vây x = {-3}}$
$\text{c) (x-3)(2x+6) =0}$
$\text{<=>\(\left[ \begin{array}{l}x-3=0\\2x+6=0\end{array} \right.\) }$
$\text{<=> \(\left[ \begin{array}{l}x=3\\x=-3\end{array} \right.\) }$
$\text{Vậy x = { 3 ;-3} }$