Question

Se (a+1)/(2-3a)= 16/9 , qual é o valor de  4/(1-2a) ? 

Answer 1

Multiplica cruzado:
16(2 - 3a) = 9(a + 1)
32 - 48a = 9a + 9
-48a - 9a = 9 - 32
- 57a = -23
a = $\frac{23}{57}$



$\frac{4}{1-2a} =\\ \\ \frac{4}{1 - 2(\frac{23}{57})}=\\ \\ \frac{4}{1-\frac{46}{57}}=\\ \\ \frac{4}{\frac{57-46}{57}} =\\ \\ \frac{4}{\frac{11}{57}}=\\ \\ 4 *\frac{57}{11}=\\ \\ \frac{228}{11}$