Question

Ma ajutati? Multumesc..
Fie proportia $\frac{x-1}{3} = \frac{4}{5}$
a) x=...
b) $x^{-1} - \frac{5}{17} =..$
c) $\frac{1}{17} x : 5^{-1}$

Answer 1

⇒5(x-1)=3·4
5x-5=12⇒5x=12+7
5x=17⇒x=17/5⇒   x=3,4
b) ⇒1/x-5/17=17-5x=0⇒
-5x=-17      ·(-1)
x=17/5
c)⇒x/17:1/5=x/17·5/1=5x/17