Chiều cao của mực nước là:

2,4 : 2 : 1,5 = 0,8 (m)

Kết luận:... 

\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x-1\right)-\left(x-6\right)\\ \Leftrightarrow6x^2+31x+18-6x^2-13x-2=x-1-x+6\\ \Leftrightarrow18x+16=5\\ \Leftrightarrow18x=-11\\ \Leftrightarrow x=-\dfrac{11}{18}\)

\(\dfrac{1}{4}+\dfrac{8}{9}\le\dfrac{x}{36}\le1-\left(\dfrac{3}{8}-\dfrac{5}{6}\right)\\ \Rightarrow\dfrac{41}{36}\le\dfrac{x}{36}\le\dfrac{35}{24}\\ \Rightarrow\dfrac{82}{72}\le\dfrac{2x}{72}\le\dfrac{105}{72}\\ \Rightarrow41\le x< 51,5\)

\(\dfrac{1}{4}+\dfrac{8}{9}\le\dfrac{x}{36}< 1-\left(\dfrac{3}{8}-\dfrac{5}{6}\right)\)

\(\Rightarrow\dfrac{41}{36}\le\dfrac{x}{36}< 1-\left(-\dfrac{11}{24}\right)\)

\(\Rightarrow\dfrac{41}{36}\le\dfrac{x}{36}< 1+\dfrac{11}{24}\)

\(\Rightarrow\dfrac{41}{36}\le\dfrac{x}{36}< \dfrac{35}{24}\)

\(\Rightarrow\dfrac{82}{72}\le\dfrac{2x}{72}< \dfrac{105}{72}\)

\(\Rightarrow82\le2x< 105\)

\(\Rightarrow41\le x< \dfrac{105}{2}\)

\(\dfrac{1}{4}+\dfrac{8}{9}\le\dfrac{x}{36}< 1-\left(\dfrac{3}{8}-\dfrac{5}{6}\right)\)

\(\dfrac{\Leftrightarrow41}{36}\le\dfrac{x}{36}< \dfrac{35}{24}\)

\(\dfrac{\Leftrightarrow82}{72}\le\dfrac{2x}{72}< \dfrac{105}{72}\)

\(\Rightarrow82\le2x< 105\)

\(\Rightarrow x=\left\{41;42;43;44;45;46;47;48;49;50;51;52\right\}\)

\(\widehat{BAM}\) = 180⁰ - 120⁰ = 60⁰

\(\widehat{BAN}\) = 100⁰ - 60⁰ = 40⁰

⇒ N₁ = \(\widehat{BAN}\) = 40⁰( hai góc đồng vị)

\(\sqrt{81}=9\\ \sqrt{\dfrac{25}{64}}=\dfrac{5}{8}\\ \sqrt{\left(-3\right)^2}=3\\ \sqrt{169}=13\\ \sqrt{0,0121}=0,11\\ \sqrt{0,49}=0,7\)

\(\widehat{ACD}\) = 180⁰ - 110⁰ = 70⁰ 

\(\widehat{DCE}\) = 180⁰ - 150⁰ = 30⁰

\(\widehat{ACE}\) = \(\widehat{ACD}\) + \(\widehat{DCE}\) = 70⁰ + 30⁰ = 100⁰

...=344-2574-344+5874=-2574+5874=3300

344-2574+(-344)+5874

= \(\left[344+\left(-334\right)\right]+\left(5874-2574\right)\)

=\(1+3300\)

=\(3300\)