Tìm x biết:
−2x+(−25)2=0,12- 2x + {\left( { - \frac{2}{5}} \right)^2} = 0,{1^2}−2x+(−52)2=0,12
340\frac{3}{{40}}403
17200\frac{{17}}{{200}}20017
−17200\frac{{ - 17}}{{200}}200−17
225\frac{2}{{25}}252
Đáp án: <p><span data-type="math-inline" data-latex="\frac{3}{{40}}">$\frac{3}{{40}}$</span></p>
Phương pháp giải:
Bước 1: Tính các lũy thừa
Bước 2: Tìm -2x
Bước 3: Tìm x
Lời giải chi tiết:
−2x+(−25)2=0,12−2x+425=1100−2x=1100−425−2x=1100−16100−2x=−15100x=−15100:(−2)x=−15100.−12x=340\begin{array}{l} - 2x + {\left( { - \frac{2}{5}} \right)^2} = 0,{1^2}\\ - 2x + \frac{4}{{25}} = \frac{1}{{100}}\\ - 2x = \frac{1}{{100}} - \frac{4}{{25}}\\ - 2x = \frac{1}{{100}} - \frac{{16}}{{100}}\\ - 2x = \frac{{ - 15}}{{100}}\\ x = \frac{{ - 15}}{{100}}:( - 2)\\ x = \frac{{ - 15}}{{100}}.\frac{{ - 1}}{2}\\ x = \frac{3}{{40}}\end{array}−2x+(−52)2=0,12−2x+254=1001−2x=1001−254−2x=1001−10016−2x=100−15x=100−15:(−2)x=100−15.2−1x=403
