Question

Se considera scădere a1-1a=18. Determina valoarea lui,, a"​

Answer 1

$\overline{a1}-\overline{1a} = 18 \\ 10\cdot a+1-(10\cdot 1+a) = 18 \\ 10a+1-10-a = 18 \\ 9a-9 = 18 \\ 9a = 27 \\ \\a = \dfrac{27}{9}\\ \\ \Rightarrow \boxed{a = 3}$