a) \(\left(\frac{2x}{3}-3\right)\div\left(-10\right)=\frac{2}{5}\)
\(\Rightarrow\left(\frac{2x}{3}-\frac{9}{3}\right).-\frac{1}{10}=\frac{2}{5}\)
\(\Rightarrow\frac{2x-9}{3}.-\frac{1}{10}=\frac{2}{5}\)
\(\Rightarrow\frac{9-2x}{30}=\frac{2}{5}\Rightarrow\left(9-2x\right).5=60\)
\(\Rightarrow45-10x=60\Rightarrow-10x=15\Rightarrow x=-\frac{15}{10}=-1,5\)
b)\(\left(x+5\right)^3=64\)
\(\Rightarrow\left(x+5\right)^3=4^3\)
\(\Rightarrow x+5=4\Rightarrow x=-1\)
A, 2x/3-3=-4
2x/3=-1
2x=-3
X=-3/2
B,(x+5)^3=4^3
=> x+5=4
X=-1
k nha