Toán bài2:tìm x biết: a)1027-4nhânx=175 B)720:[41nhân(2nhânx-5)]=2mũ3nhân5 09/07/2021 By Aubrey bài2:tìm x biết: a)1027-4nhânx=175 B)720:[41nhân(2nhânx-5)]=2mũ3nhân5
\[\begin{array}{*{20}{l}}\begin{array}{l}a)1027 – 4x = 175\\ \Leftrightarrow 4x = 1027 – 175\\ \Leftrightarrow 4x = 852\\ \Leftrightarrow x = 213\end{array}\\ {b)720:\left[ {41\left( {2x – 5} \right)} \right] = {2^3}.5}\\{ \Leftrightarrow 720:\left( {82x – 205} \right) = 40}\\{ \Leftrightarrow 82x – 205 = 18}\\{ \Leftrightarrow 82x = 18 + 205}\\{ \Leftrightarrow 82x = 223}\\{ \Leftrightarrow x = \dfrac{{223}}{8}}\end{array}\] Trả lời
a ) 1027- 4 × $x^{}$ =175 4 × $x^{}$ = 1027 – 175 4 × $x^{}$ = 852 $x^{}$ = 852 ÷ 4 $x^{}$ = 213 B ) 720: [41 × (2 ×$x^{}$ -5)]= $2^{3}$ x 5 720 : [ 41 × (2 ×$x^{}$ -5)]= 8 × 5 720 : [ 41 × (2 ×$x^{}$ -5)]=40 82 × $x^{}$ = 720 : 40 82 × $x^{}$ – 205 = 18 82 × $x^{}$ = 18 + 205 82 × $x^{}$ = 223 $x^{}$ = 223 ÷ 82 $x^{}$ = $\frac{223}{82}$ Trả lời
\[\begin{array}{*{20}{l}}
\begin{array}{l}
a)1027 – 4x = 175\\
\Leftrightarrow 4x = 1027 – 175\\
\Leftrightarrow 4x = 852\\
\Leftrightarrow x = 213
\end{array}\\
{b)720:\left[ {41\left( {2x – 5} \right)} \right] = {2^3}.5}\\
{ \Leftrightarrow 720:\left( {82x – 205} \right) = 40}\\
{ \Leftrightarrow 82x – 205 = 18}\\
{ \Leftrightarrow 82x = 18 + 205}\\
{ \Leftrightarrow 82x = 223}\\
{ \Leftrightarrow x = \dfrac{{223}}{8}}
\end{array}\]
a ) 1027- 4 × $x^{}$ =175
4 × $x^{}$ = 1027 – 175
4 × $x^{}$ = 852
$x^{}$ = 852 ÷ 4
$x^{}$ = 213
B ) 720: [41 × (2 ×$x^{}$ -5)]= $2^{3}$ x 5
720 : [ 41 × (2 ×$x^{}$ -5)]= 8 × 5
720 : [ 41 × (2 ×$x^{}$ -5)]=40
82 × $x^{}$ = 720 : 40
82 × $x^{}$ – 205 = 18
82 × $x^{}$ = 18 + 205
82 × $x^{}$ = 223
$x^{}$ = 223 ÷ 82
$x^{}$ = $\frac{223}{82}$