a) \(\left( { - 2,259} \right) +31,3 =  31,3 - 2,259 = 29,041\)

b) \(\left( { - 0,325} \right) - 11,5 = -(0,325 + 11,5) = -11,825\)

a: =32+1,6=33,6

b: =-0,5x1,23=-0,615

c: =-2,3-7,7=-10

d: =0,325-3,21=-2,885

a) \(\dfrac{2\left(x-2\right)}{x\left(x-2\right)}=\dfrac{2}{x}\)

\(a,=\dfrac{2\left(x-2\right)}{x\left(x-2\right)}=\dfrac{2}{x}\\ b,=\dfrac{\left(1-3x\right)\left(2x-1\right)+2x\left(3x-2\right)-\left(3x-2\right)}{2x\left(2x-1\right)}\\ =\dfrac{\left(1-3x\right)\left(2x-1\right)+\left(2x-1\right)\left(3x-2\right)}{2x\left(2x-1\right)}\\ =\dfrac{\left(2x-1\right)\left(1-3x+3x-2\right)}{2x}=\dfrac{-1}{2x}\)

a \(\dfrac{2x-4}{x^2-2x}\)= \(\dfrac{2\left(x-2\right)}{x\left(x-2\right)}\)=\(\dfrac{2}{x}\)

Lời giải:

$(2x-3)(x^2+1)=0$

\(\Leftrightarrow \left[\begin{matrix} 2x-3=0\\ x^2+1=0\end{matrix}\right.\Leftrightarrow \left[\begin{matrix} x=\frac{3}{2}(\text{chọn})\\ x^2=-1<0(\text{vô lý})\end{matrix}\right.\)

Vậy pt có nghiệm $x=\frac{3}{2}$

\(\dfrac{2}{x+1}-\dfrac{1}{x-2}=\dfrac{3x-11}{\left(x+1\right)\left(x-2\right)}\\ \Leftrightarrow\dfrac{2.\left(x-2\right)}{\left(x+1\right)\left(x-2\right)}-\dfrac{1.\left(x+1\right)}{\left(x+1\right)\left(x-2\right)}=\dfrac{3x-11}{\left(x+1\right)\left(x-2\right)}\\ \Leftrightarrow2x-4-x+1=3x-11\\ \Leftrightarrow x-3=3x-11\\ \Leftrightarrow x-3x=-11+3\\ \Leftrightarrow-2x=-8\\ \Leftrightarrow x=4\)

Vậy tập nghiệm của phương trình là S = { 4 }

a: Bậc là 3

\(\Leftrightarrow x\cdot\dfrac{18}{5}+x\cdot\dfrac{17}{6}-x\cdot\dfrac{10}{7}+x\cdot\dfrac{1}{8}=\dfrac{15}{8}\)

\(\Leftrightarrow x\cdot\dfrac{4309}{840}=\dfrac{15}{8}\)

=>x=1575/4309