x3 - 6 = 90

=> x * 3 = 90 + 6

=> x * 3 = 96

=> x = 96 : 3

=> x = 32

k mk mk k lại

\(A=\frac{3}{4}\times\frac{5}{9}+\frac{\frac{5}{2}-\frac{1}{2}}{2}\)

\(\Rightarrow A=\frac{5}{12}+\frac{\frac{4}{2}}{2}\Rightarrow A=\frac{5}{12}+\frac{2}{2}\Rightarrow A=\frac{5}{12}+1\Rightarrow A=\frac{17}{12}\)